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GB/T 3883.311-2019 (GB/T3883.311-2019)

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GB/T 3883.311-2019: PDF in English (GBT 3883.311-2019)

GB/T 3883.311-2019
Safety of motor-operated hand-held, transportable and garden tools - Part 311.Particular requirements for transportable cut-off machines
ICS 25.140.20
K64
National Standards of People's Republic of China
Replace GB/T 13960.11-2000
Safety of hand-held and portable electric tools and garden tools
Part 311.Special requirements for portable profile cutting machines
2019-10-18 released
2020-05-01 Implementation
State Administration for Market Regulation
Issued by China National Standardization Administration
Table of contents
Foreword Ⅰ
Introduction Ⅲ
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 General requirements 2
5 Test general conditions 2
6 Radiation, toxicity and similar hazards 2
7 Category 3
8 Signs and instructions 3
9 Protection against touching live parts 5
10 Start 5
11 Input power and current 5
12 Fever 5
13 Heat resistance and flame resistance 5
14 Moisture resistance 5
15 Rust prevention 6
16 Overload protection of transformers and related circuits 6
17 Durability 6
18 Abnormal operation 6
19 Mechanical hazards 6
20 Mechanical strength 10
21 Structure 11
22 Internal wiring 11
23 Components 11
24 Power connection and external flexible cord 11
25 Terminals for external wires 11
26 Grounding device 12
27 Screws and connectors 12
28 Creepage distance, electrical clearance and insulation penetration distance 12
Appendix 18
Appendix I (Informative Appendix) Measurement of Noise and Vibration 19
Appendix K (Normative Appendix) Battery-powered tools and battery packs 20
Reference 21
Preface
Part 3 of "Safety of Handheld, Portable Power Tools and Garden Tools" Portable power tools currently consists of the following 2 parts
composition.
---GB/T 3883.306-2017 The safety of hand-held and portable electric tools and garden tools-Part 3.Portable liquid carrying
Special requirements for source diamond drills;
Special requirements for wood cutting machines.
This part is part 311 of GB/T 3883.
This section was drafted in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 13960.11-2000 "Safety of portable electric tools Part 2.Special requirements for profile cutting machines",
Compared with GB/T 13960.11-2000, the main technical changes are as follows.
---The scope of application is to increase cutting objects such as concrete and masonry, increase the use of diamond cutting wheels, and clarify the type and line of grinding wheels used
Speed and range, increase the non-applicable range of this part (see Chapter 1);
--- The term "inner flange", "consolidated enhanced grinding wheel", "cutting device", "D", "diamond cutting wheel", "grid", "outer flange" and "stop
Rest position"; modify the terms "profile cutting machine" and "grinding wheel guard"; delete the terms "spindle", "clamping plate assembly" and "straight edge groove clamp"
Squeeze plate" and "workpiece fixture" (see Chapter 3, Chapter 2 of the.2000 edition);
---Add the description of the parts that should be included in the tool quality in the general conditions of the test (see Chapter 5);
--- Abnormal operation modify Table 4 in Part 1 (see Chapter 18);
---Mechanical hazards 19.6 increase the prevention of overspeed test; 19.7 increase the prevention of tipping test and facilitate the fixing of tools; 19.101.1
Increase the general requirements for grinding wheel protection; modify the original 18.1.103, 18.1.104 and 20.17 to 19.101.2, that is, to improve the grinding wheel guard
Seek; modify the original 18.104 to 19.101.3, and improve the protection of the grinding wheel under the table; modify the original 18.1.105 to 19.102, which is complete
Improve the deflection of spark splash; modify the original 18.101 to 19.103, that is, improve the fixation of the workpiece; increase the installation of the 19.104 accessory; repair
Change the original 18.102 to 19.105.1 and 19.105.2, that is, improve the general requirements and minimum dimensions of the flange; add 19.105.3 diamond
The size requirements for the flange of the stone cutting wheel; add 19.105.4 flange strength test; modify 18.103 to 19.106, and improve the tool master
Shaft requirements (see Chapter 19, Chapter 18 of the.2000 edition);
---Mechanical strength was revised from 18.1.102 to 20.101 and 20.102, and the strength requirements for the wheel guard were improved (see Chapter 20,.2000 edition
Chapter 18);
--- The structure is revised from 20.18 of the original Part 1 to 21.18.2.1, and the requirements for the power switch are improved; the discomfort corresponding to Part 1 is added
Terms of use (see Chapter 21, Chapter 20 of the.2000 edition);
--- The component increases corresponding to 23.3 of Part 1 (see Chapter 23);
---The power connection and external flexible cord are modified from the original 23.2 to 24.4, that is, the requirements for the power cord material are improved (see Chapter 24,.2000 edition
Chapter 23);
---Add informative Appendix I "Measurement of Noise and Vibration" (see Appendix I).
The translation method used in this part is equivalent to the IEC 62841-3-10.2015 "Motor-driven handheld and portable electric tools and gardens
Machine Safety Part 3-10.Special Requirements for Portable Profile Cutting Machines.
The Chinese documents that have a consistent correspondence with the international documents cited in this section are as follows.
---GB/T 4127.15-2007 Fixed size of abrasive tools Part 15.Cutting wheels for stationary or mobile cutting machines
(ISO 603-15.1999, MOD)
---GB/T 34560 (all parts) structural steel [ISO 630 (all parts)]
This section has made the following editorial changes.
--- Amend the standard name to "Safety of hand-held, portable electric tools and garden tools Part 311.Movable profile cutting
Special requirements for cutting machines";
---This part incorporates the content of IEC 62841-3-10.2015/COR1.2016, and the clauses involved in these technical corrections have been passed
It is marked by the vertical double line (‖) on the outer margin position;
---There is an error in the international standard. Now the 8mm metric system in Table 102 is changed to 5/16in from 2in.
This part shall be in accordance with GB/T 3883.1-2014 "Safety of Hand-held and Portable Electric Tools and Garden Tools Part 1.General Requirements"
Seek to be used together.
This part specifies the "applicable" part, which means that the corresponding clause in GB/T 3883.1-2014 applies; this part specifies the "replacement" part,
The clauses in this part shall prevail; the part in this part with “modification” indicates the relevant clauses of GB/T 3883.1-2014
The content should be subject to the revised content of this section, and the other content in this clause still applies; the “additional” part in this section means that except
In addition to complying with the corresponding provisions of GB/T 3883.1-2014, it should also comply with the additional provisions of this section.
This part was proposed by China Electrical Equipment Industry Association.
This part is under the jurisdiction of the National Electric Tool Standardization Technical Committee (SAC/TC68).
Drafting organizations of this section. Hongda Group Co., Ltd., Shanghai Electric Tool Research Institute (Group) Co., Ltd., Ruiqi Holding Co., Ltd.
Company, Zhengyang Technology Co., Ltd., Zhejiang Xinyuan Electric Manufacturing Co., Ltd., Baoshide Technology (China) Co., Ltd.
The main drafters of this section. Yao Xucheng, Gu Jing, Zhu Xianbo, Xu Feihao, Chen Huazheng, Ding Yucai, Cao Zhenhua, Yao Tongsuo, Chen Jianqiu.
The previous releases of the standards replaced by this part are.
---GB/T 13960.11-2000;
---GB 14807-1993.
introduction
In.2014, my country issued the national standard GB/T 3883.1-2014 ``Safety No. of Handheld and Portable Power Tools and Garden Tools''
Part 1.General Requirements, the original GB/T 3883 (part of hand-held power tools), GB/T 13960 (part of portable power tools) and
The common technical requirements of the general safety standards of the three series of electric tools in GB/T 4706 (only for garden electric tools) have been integrated.
There are 3 parts in the special requirements for specific types of small products used in conjunction with GB/T 3883.1-2014, which are Part 2 (Hand
Portable power tools section), section 3 (portable power tools section), and section 4 (garden power tools section), all transform the corresponding countries
The specific requirements of the international standard IEC 62841 series.
The main element of the standard name is expanded to "safety of hand-held and portable electric tools and garden tools", and the original hand-held electric tools are used
Part of the standard number GB/T 3883.The standard sub-part number of each sub-category product consists of 3 digits, of which the first digit
Indicates the corresponding part, the 2nd and 3rd digits indicate different small products.
The new version of the GB/T 3883 series of standards will form a more scientific, complete, universal, and unified series of safety standards for electric tool products
The system makes the implementation of the standard more practical and convenient to use.
At present, the new version of GB/T 3883 series standard "portable electric tools part" has published standards as follows.
---GB/T 3883.306-2017 The safety of hand-held and portable electric tools and garden tools-Part 3.Portable liquid carrying
Special requirements for source diamond drills (instead of GB/T 13960.7-1997);
Special requirements for wood cutting machines (instead of GB/T 13960.11-2000).
The following standards will be revised in the future.
---GB/T 13960.2-2008 Safety of portable electric tools Part 2.Special requirements for circular saws;
---GB/T 13960.3-1996 Special requirements for safe rocker saws for portable power tools;
---GB/T 13960.4-2009 Safety of portable electric tools Part 2.Special requirements for planing and thickness planing;
---GB/T 13960.5-2008 Safety of portable electric tools Part 2.Special requirements for bench grinders;
---GB/T 13960.6-1996 Special requirements for safety band saws for portable power tools;
---GB/T 13960.8-1997 Safety of portable electric tools Part 2.Special requirements for diamond saws with water source;
---GB/T 13960.9-1997 Safety of portable electric tools Part 2.Special requirements for oblique cutting machines;
---GB/T 13960.10-2009 Safety of portable electric tools Part 2.Special requirements for single-axis vertical wood milling;
---GB/T 13960.13-2005 The second part of the safety of portable electric tools. the special requirements for the oblique cutting bench combination saw.
Safety of hand-held and portable electric tools and garden tools
Part 311.Special requirements for portable profile cutting machines
1 Scope
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
increase.
This part is applicable to a portable profile cutting machine used for cutting metal, concrete, masonry and other materials, equipped with a piece of the following types of grinding wheels.
---41 type consolidation reinforced grinding wheel; or
---Diamond cutting wheel, if there is a circumferential groove, the width does not exceed 10mm;
and
---The maximum diameter of the grinding wheel at the rated no-load speed, the linear speed of the edge of the grinding wheel does not exceed 100m/s; and
---The diameter of the grinding wheel ranges from 250mm to 410mm.
Note 1.Unless otherwise specified, the "grinding wheel" in this section includes the "41 type consolidated reinforced grinding wheel" and "diamond cutting wheel" specified in the scope.
This section does not apply to.
---Removable miter saw;
---Removable ceramic tile cutter;
---Removable metal saw.
Note 2.The portable miter saw is covered by IEC 62841-3-9, and the portable tile cutter and portable metal saw are part of the future IEC 62841-3
cover.
2 Normative references
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
increase.
ISO 603-15 Bonded Abrasive Product Dimensions Part 15.Cutting wheels for stationary or mobile cutting machines
ISO 630 (all parts) structural steel
3 Terms and definitions
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
3.101
Inner flange
Contact and support the parts on the back of the grinding wheel, and are located on the spindle between the grinding wheel and the tool.
3.102
Consolidation enhanced grinding wheel
Grinding wheels that comply with ISO 603-15 and have different purposes.
3.103
Profile cutting machine
A tool for cutting through a rotating consolidation-enhanced grinding wheel or diamond cutting wheel. The grinding wheel is fixed on the main shaft of the cutting device. work
The tool is equipped with a base to support and place the workpiece fixed by the clamping device, the cutting device is fixed on the cantilever, and the cantilever passes through the base or tool
The fulcrum on the bracket protrudes above the base.
Note. See Figure 101.
3.104
Cutting device
A device equipped with an additional grinding wheel can produce cutting action.
3.105
The maximum specified grinding wheel diameter.
3.106
Diamond cutting wheel
Metal cutting wheels with sanded edges, the edges are continuous or notched.
3.107
Fence
A device that positions the workpiece and bears the horizontal force generated by the grinding wheel during the cutting process.
3.108
Outer flange
Support the parts on the front side of the grinding wheel, and fix and clamp the grinding wheel on the main shaft and inner flange.
3.109
Resting position
The highest position of the cutting device determined by the design.
3.110
Wheel guard
A shield that partially encases the grinding wheel to protect the operator.
4 General requirements
This chapter of GB/T 3883.1-2014 applies.
5 Test general conditions
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
5.17 Added.
The quality of the tool should include the wheel guard and the backing grid.
Other parts required by the instruction manual, such as handling devices, should also be included in the quality of the tool.
6 Radiation, toxicity and similar hazards
This chapter of GB/T 3883.1-2014 applies.
7 categories
This chapter of GB/T 3883.1-2014 applies.
8 Signs and instructions
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
8.1 Added.
Tools should be marked with.
---The rated no-load speed of the output shaft.
8.2 Added.
Tools should be marked with the following safety warnings.
"Warning-Always wear protective goggles" or ISO 7010 M004 symbol or the following safety signs.
Goggles logo can be modified, for example, add other personal protective equipment such as ear protection, dust mask and other logos.
8.3 Add.
The tool should also be marked with the following additional information.
--- Wheel diameter D;
---The direction of rotation of the grinding wheel should be indicated by raised or recessed arrows or other equivalent clear and durable methods.
8.14.1 Added.
The safety instructions added in 8.14.1.101 shall be given. This part can be printed separately from the "General Safety Warning for Power Tools".
For all warnings in 8.14.1.101, the word "cutting device" can be replaced with another appropriate word at the choice of the producer.
8.14.1.101 Safety instructions for profile cutting machine
1) Safety warning of profile cutting machine
a) The operator and bystanders should stay away from the rotating cutting surface of the grinding wheel. The guard helps protect the operator from being hit by grinding wheel debris
And accidentally touch the grinding wheel.
b) Only use consolidation-enhanced grinding wheels or diamond cutting wheels suitable for this tool. Other attachments that can be installed on this tool
The software cannot guarantee safe operation.
Note 1.The applicability of the term "consolidation enhancement" or "diamond" is determined according to the function of the tool.
c) The rated speed of the accessory should be at least equal to the maximum speed marked by the tool. If the attachment speed exceeds its rated value, it will break and
Splash.
d) The grinding wheel should be used according to the application method recommended by the manufacturer. For example, do not use the end face of the grinding wheel for grinding. The grinding wheel is round
When working on the peripheral surface, the lateral force exerted on the grinding wheel will cause the grinding wheel to break.
e) Always use a good grinding wheel flange, and its diameter should match the selected grinding wheel. Suitable grinding wheel flange can support the grinding wheel
And reduce the possibility of grinding wheel breakage.
f) The outer diameter and thickness of the selected accessories should be within the rated value of the tool. Accessories with incorrect dimensions are not properly protected
Protection and control.
g) The aperture of the grinding wheel and flange should match the output shaft of this tool. The difference between the grinding wheel and flange shaft hole and the installation part of this tool
Matching can cause imbalance, excessive vibration, and may lead to loss of control.
h) Do not use damaged grinding wheels. Check the grinding wheel for nicks and cracks before each use. If the tool or grinding wheel falls,
To check whether the grinding wheel is damaged or install a good grinding wheel. After checking and installing the grinding wheel, the operator and bystanders
Keep away from the plane where the rotating grinding wheel is located, and run the tool at the maximum no-load speed for 1 min. Usually, the damaged grinding wheel
A burst occurred during this test period.
i) Wear personal protective equipment. According to the occasion, wear a face shield, goggles or safety glasses. Depending on the situation, wear
Dust masks, earmuffs, gloves, and aprons that can block small fragments of the grinding wheel or workpieces. Eye protection should be able to block all kinds of
Flying debris generated during operation. The face mask or mask should be able to filter the particles generated during operation. Prolonged exposure to high intensity noise
May cause hearing loss.
j) Keep bystanders a safe distance from the work area. Anyone entering the work area must wear personal protective equipment. Artifact
Or fragments of the bursting grinding wheel may fly out, causing injuries near the operating area.
k) Keep the power cord away from rotating accessories. If the operator loses control, the power cord may be cut or broken, the operator's hand or arm
It may be caught in the rotating grinding wheel.
l) Clean the vent of the tool regularly. The motor fan will suck dust into the casing, and excessive accumulation of metal dust may produce
Electrical hazard.
m) Do not operate tools near flammable materials. Do not operate the tool when it is placed on the surface of combustible materials such as wood. spark
Easy to ignite these materials.
n) Do not use accessories that require liquid coolant. Using water or other liquid coolants may cause
electric shock.
Note 2.This warning does not apply to tools with a fluid supply system design.
2) Rebound and related warnings
Rebound is the reaction force suddenly produced when the rotating grinding wheel is squeezed or stuck. The rotating grinding wheel will quickly produce after being squeezed or jammed
Blocking, and then causing the cutting device to lose control and forced to rebound upward to the operator.
For example, if the grinding wheel is stuck or squeezed by the workpiece, the edge of the grinding wheel entering the nip point will dig into the surface of the material, causing the grinding wheel to crawl out or reverse.
bomb. In this case, the grinding wheel may break.
Rebound is the result of abuse of tools and/or incorrect operating procedures or conditions. Rebound can be avoided by taking the following appropriate precautions.
a) Hold the tool tightly and place your body and arms to resist rebound force. If appropriate measures are taken, the operator can control upward
The rebound force.
b) Do not align the operator's body with the rotating surface of the grinding wheel. If rebound occurs, it will force the cutting device to rebound upward to the operator.
c) Do not install saw chains, woodworking carving blades, diamond cutting wheels or toothed saw blades with a circumferential groove width exceeding 10mm. These ones
Accessories often cause rebound and loss of control.
d) Do not "block" the grinding wheel or apply excessive force. Don't try to make too deep cuts. Excessive force on the grinding wheel will cause the grinding wheel to
It is easier to twist or jam during cutting and increase the possibility of rebound or grinding wheel breakage.
e) When the grinding wheel is stuck or cutting is interrupted for various reasons, turn off the tool and keep the cutting device stationary until the grinding wheel stops completely
Until the next. Do not try to move the running wheel during the cutting process, otherwise rebound may occur. Check and respond
Measures for the wheel jam.
f) Do not restart the cutting operation when the grinding wheel is in the workpiece. After the grinding wheel reaches full speed, cut carefully. When the wheel
When the tool is restarted while in the workpiece, the grinding wheel may be stuck, upward or rebound.
g) Support oversized workpieces to reduce the risk of the grinding wheel being stuck or rebounding. Large workpieces will sink due to their own weight.
On both sides, the lower part of the workpiece near the cutting line and the edge of the workpiece should be supported.
8.14.2a) Added.
101) A description of the permitted accessories (diamond cutting wheel or consolidated reinforced grinding wheel), the diameter of the grinding wheel, the thickness of the grinding wheel and the hole diameter.
Description of diamond cutting wheel.
---The maximum width of the circumferential groove should be 10mm;
---The forward inclination angle (of the diamond layer) should be negative.
See Figure 102.
102) The term "consolidated enhanced grinding wheel" or the explanation of the designated model, if applicable.
103) If the profile cutting machine is used on a workbench or similar table, make sure that the profile cutting machine is always placed on a stable surface
And instructions on how to fix the tool.
104) Information about the maximum cutting capacity when the tool is at 0° and the maximum inclination angle.
8.14.2b) Added.
101) If the liner is provided with the consolidated reinforced grinding wheel, there should be instructions for proper use of the liner.
102) Instructions on installing accessories, using the correct flange and carefully using the grinding wheel. Reversible flanges should be installed correctly
instruction of.
103) The instructions for the operator to use all the different types of grinding wheels specified in the 8.14.2a) 101) instructions, for example, consolidation enhancement
Type grinding wheel, diamond cutting wheel.
104) Instructions on how to fix and support the workpiece.
105) Instructions for wearing personal protective equipment.
---Earmuffs;
---Wear gloves when cutting.
8.14.2c) Added.
101) Instructions for storage and disposal of accessories.
9 Protection against touching live parts
This chapter of GB/T 3883.1-2014 applies.
10 Start
This chapter of GB/T 3883.1-2014 applies.
11 Input power and current
This chapter of GB/T 3883.1-2014 applies.
12 fever
This chapter of GB/T 3883.1-2014 applies.
13 Heat resistance and flame resistance
This chapter of GB/T 3883.1-2014 applies.
14 Moisture resistance
This chapter of GB/T 3883.1-2014 applies.
15 Anti-rust
This chapter of GB/T 3883.1-2014 applies.
16 Overload protection of transformers and related circuits
This chapter of GB/T 3883.1-2014 applies.
17 Durability
This chapter of GB/T 3883.1-2014 applies.
18 Abnormal operation
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
18.8 Replace Table 4 with.
Table 4 Required performance levels
Type and role of safety critical function (SCF) Minimum allowable performance level (PL)
Power switch-prevent undesired turn-on Use 18.6.1 fault condition assessment, SCF should not be missing
Power switch-provide the expected disconnection with 18.6.1 fault condition evaluation, SCF should not be missing
Any electronic controller that passed the 18.3 test c
Overspeed protection to prevent the output speed from exceeding 120% of the rated (no-load) speed
Provide the desired direction of rotation b
21.18.2.3 required disconnect lock function b
Prevent exceeding the thermal limit in Chapter 18a
23.3 Required prevention of self-reset a
19 Mechanical hazards
In addition to the following clauses, this chapter of GB/T 3883.1-2014 applies.
19.1 Added.
This article does not apply to the protection provided to prevent personal injury caused by the grinding wheel.
Note. The requirements for grinding wheel protection are specified by 19.101.
19.6 Replacement.
The tool should be designed to prevent overspeed under normal use. Under any operating conditions, the speed of the tool should not exceed the
Load speed.
Check by observing and measuring the speed of the tool after running for 5 minutes. The recommended accessories that will produce the highest speed should be installed.
If the tool is equipped with a load-sensitive speed controller, there is no need to install accessories for loading to reach the maximum speed.
19.7 Added.
19.7.101 The profile cutting machine shall be constructed so that it will not tip over under foreseeable use.
It is checked by the following test. The tools are assembled according to the instructions in 8.14.2a)2).
Place the profile cutting machine on a horizontal medium density board (MDF) with a density of 650kg/m3~850kg/m3, not fixed to the supporting surface.
The grid is fixed at the position closest to the fulcrum of the base. Without installing the workpiece, press the cutting device to the lowest cutting position, and then release the handle. Profile
The cutting machine should not tip over.
19.7.102 It should be convenient to fix the profile cutting machine to the worktable to avoid movement, for example, with mounting holes or clamping surfaces on the base.
19.101 Wheel protection
19.101.1 General requirements
The protective device of the tool should protect the operator during normal use to prevent.
--- Accidentally touching the grinding wheel;
---Injection of grinding wheel fragments;
---Mars and other debris.
The shield should meet the following requirements.
--- When replacing the grinding wheel, it should not be necessary to remove the guard from the tool.
---The design should facilitate the replacement of the grinding wheel. For this reason, as long as part of the shield is connected to the shield in any way, it can be used without tools
Open that part of the shield.
---Its design can minimize the risk of the operator accidentally touching the grinding wheel during normal use.
Should be at least in one position, through the fixed device related to the spindle to limit the installation of oversized grinding wheels. A new grinding wheel with diameter D,
The maximum gap between its circumference and the device should not exceed 12mm.
The protective device shall meet the requirements of 19.101.2 and 19.101.3.
Check by observation and measurement.
19.101.2 Design requirements for grinding wheel guards
19.101.2.1 The tool shall enclose area 1, area 2 and area 3 shown in Figure 103 by a combination of fixed and movable shields.
When the cutting device is in the fully depressed position, area 1 is the area above the straight line parallel to the base and passing through the center of the grinding wheel. Dang Che
When the cutting device is in any position, except for the end of the spindle, the nut and the outer flange, the side and circumferential surface of the grinding wheel in zone 1 should be protected.
If the spindle end, nut or outer flange is not round, they should also be protected.
When the cutting device is in the resting position, zone 2 is at the front end of the tool, and is located in zone 1 and a straight line parallel to the base and passing through the center of the grinding wheel.
At least 15° below the line [angle β] of Fig. 103b). In the resting position, the protection of zone 2 should enable the wheel guard to protect the wheel
At least 20% of the radius of the circumference and sides close to the edge.
When the cutting device is in the fully depressed position, zone 3 is at the rear end of the tool, and is located in zone 1 an......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.