|
US$359.00 · In stock
Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 23567.2-2018: Reliability evaluation for numerical control machine tools -- Part 2: Machining centres
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB/T 23567.2-2018 | English | 359 |
Add to Cart
|
4 days [Need to translate]
|
Reliability evaluation for numerical control machine tools -- Part 2: Machining centres
| Valid |
GB/T 23567.2-2018
|
PDF similar to GB/T 23567.2-2018
Basic data | Standard ID | GB/T 23567.2-2018 (GB/T23567.2-2018) | | Description (Translated English) | Reliability evaluation for numerical control machine tools -- Part 2: Machining centres | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | J50 | | Classification of International Standard | 25.040.20 | | Word Count Estimation | 18,194 | | Date of Issue | 2018-05-14 | | Date of Implementation | 2019-02-01 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | GB/T 23567.2-2018: Reliability evaluation for numerical control machine tools -- Part 2: Machining centres
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Reliability evaluation for numerical control machine tools--Part 2. Machining centres
ICS 25.040.20
J50
National Standards of People's Republic of China
CNC machine tool reliability assessment
Part 2. Machining Center
Part 2. Machiningcentres
Published on.2018-07-13
Implementation of.2019-02-01
State market supervision and administration
China National Standardization Administration issued
Content
Foreword I
1 Scope 1
2 Normative references 1
3 Terms and Definitions 1
4 Test method 3
5 Test requirements 4
6 Test method 5
7 Data collection and recording 7
8 Reliability Assessment 7
Appendix A (informative) Reliability Test Record 9
Appendix B (normative appendix) Reliability factor k and number of failures rs 14
Foreword
GB/T 23567 "Reliability Evaluation of CNC Machine Tools" is divided into the following eight parts.
--- Part 1. General;
--- Part 2. Machining Center;
--- Part 3. CNC lathes and turning centers;
--- Part 4. CNC milling machine;
---Part 5. CNC grinding machine;
---Part 6. CNC gear processing machine;
---Part 7. Five-axis linkage machine tool;
--- Part 8. Composite processing machine tools.
This part is the second part of GB/T 23567.
This part is drafted in accordance with the rules given in GB/T 1.1-2009.
This part was proposed by the China Machinery Industry Federation.
This part is under the jurisdiction of the National Technical Committee for Standardization of Metal Cutting Machines (SAC/TC22).
This section drafted by. National Machine Tool Quality Supervision and Inspection Center, Tsinghua University.
Drafters of this section. Zhao Qinzhi, Wang Liping, Zhang Wei, Guan Duanyang, Wang Junjian, Chen Ruyan, Li Shulin.
CNC machine tool reliability assessment
Part 2. Machining Center
1 Scope
This part of GB/T 23567 stipulates that the machining center (hereinafter referred to as the machine tool) is performing reliability verification, measurement, identification and evaluation.
Timed test methods, test requirements, test methods, data collection and recording, reliability assessment.
This section applies to the reliability verification, measurement, identification and assessment of the machining center products.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
GB/T 2900.13-2008 Electrotechnical terminology credibility and service quality
GB 5226.1-2008 Mechanical electrical safety machinery and electrical equipment - Part 1. General technical conditions
GB/T 6477-2008 Metal cutting machine terminology
GB/T 18400.1-2010 Inspection conditions for machining centers - Part 1. Geometrical inspection of machine tools with horizontal and additional spindle heads
(horizontal Z axis)
GB/T 18400.2-2010 Inspection conditions for machining centers - Part 2. Universal or heads
Geometric accuracy test (vertical Z axis)
GB/T 18400.4-2010 Inspection conditions for machining centers - Part 4. Alignment accuracy and repetitive positioning of linear and rotary axes
Degree test
GB/T 18400.7-2010 Inspection conditions for machining centers - Part 7. Accuracy testing of finished specimens
GB 18568-2001 Processing center safety protection technical conditions
GB/T 20957.1-2007 Inspection conditions for precision machining centers - Part 1
Test (horizontal Z axis)
GB/T 20957.2-2007 Precision machining centres - Test conditions - Part 2. Vertical or universal spindle heads with vertical main rotary
Machine geometry accuracy test (vertical Z axis)
GB/T 20957.4-2007 Inspection conditions for precision machining centers - Part 4. Positioning accuracy and repeatability of linear and rotary axes
Bit accuracy test
GB/T 20957.7-2007 Inspection conditions for precision machining centers - Part 7
GB/T 21012-2007 Precision Machining Center Technical Conditions
GB/T 23567.1-2009 Reliability assessment for CNC machine tools - Part 1. General
JB/T 8801-2017 Processing Center Technical Conditions
JB/T 10793.1-2007 High-precision machining centers - Part 1. Accuracy testing for horizontal machine tools
JB/T 10793.2-2007 High-precision machining centers - Part 2. Accuracy testing of vertical machine tools
JB/T 10793.3-2017 High-precision machining center Part 3. Technical conditions
3 Terms and definitions
GB/T 2900.13-2008, GB/T 6477-2008, GB/T 23567.1-2009 and the following terms and definitions apply to this
file. For ease of use, some of the terms and definitions in GB/T 2900.13-2008 and GB/T 6477-2008 are repeated below.
3.1
Machining center machiningcenters, NCmachinetoolswithautomatictoolchanger
It is a CNC machine tool. The spindle is usually horizontal or vertical and has two or more machining methods (such as milling, boring,
Drilling), through the machining program, automatic tool change from a magazine or similar storage unit. The machine can also be artificial within a certain range.
control.
[GB/T 6477-2008, definition 2.1.28]
3.2
Failure failure
The ability of the product to complete the required function is interrupted.
Note 1. After failure, the product is in a fault state.
Note 2. The difference between “failure” and “fault” is that the failure is an event and the failure is a state.
Note 3. The “failure” defined here does not apply to products consisting only of software.
[GB/T 2900.13-2008, definition 191-04-01]
3.3
Design failure designfault
Failure caused by improper product design.
[GB/T 2900.13-2008, definition 191-05-09]
3.4
Manufacturing fault manufacturingfault
Failure due to failure to manufacture the product in accordance with the design or specified process.
[GB/T 2900.13-2008, definition 191-05-10]
3.5
Intermittent fault
Appears for a limited period of time, and subsequent failure of the product to restore the required function without any repairs.
Note. This type of fault is often reproduced.
[GB/T 2900.13-2008, definition 191-05-17]
3.6
Failure mode faultmode
One of the possible states of a faulty product for a given requested function.
[GB/T 2900.13-2008, definition 191-05-22]
3.7
Fault recognition faultrecognition
Identify faulty events.
[GB/T 2900.13-2008, definition 191-07-20]
3.8
Failure cause failurecause
Factors that cause failure during design, manufacture, or use.
[GB/T 2900.13-2008, definition 191-04-17]
3.9
Failure mechanism failuremechanism
A physical, chemical, or other process that causes failure.
[GB/T 2900.13-2008, definition 191-04-18]
3.10
Conformity test compliance test
A test indicating whether a certain characteristic or a certain property of a product meets the stated requirements.
[GB/T 2900.13-2008, definition 191-14-02]
3.11
Simulation field test simulationfieldtest
Compliance tests or test tests performed under specified and controlled conditions (with or without simulating actual field conditions).
Note. Rewrite GB/T 2900.13-2008, definition 191-14-04.
3.12
Tracking statistics field test trackingofstatisticalfieldtest
Compliance testing or testing conducted by tracking and statistical methods at the user site where work, environment, maintenance and measurement conditions are recorded
Test.
Note. Rewrite GB/T 2900.13-2008, define 191-14-05.
3.13
Quick test quicktest
In order to shorten the controllability test process, under the working mechanism of the machine tool and the safety margin, the applied load level exceeds the normal work of the machine tool.
Do a horizontal test.
4 test method
4.1 Test plan
4.1.1 Test selection
The machine reliability test method, the simulation field test and the tracking and field test are optional.
4.1.2 Simulation field test
For newly developed and newer machine tools, a simulated field test with no replacement timing censoring test should be used. Simulated field test
Should be a continuous reliability test.
4.1.3 Tracking Statistics Field Test
For mass-produced machine tools, time-crunting or fixed-crunch tracking statistical field tests should be used.
4.1.4 Retesting
If the test is stopped midway through various reasons, the test should be repeated.
4.2 Timing Censoring Test Time
4.2.1 Simulated field test in a fast mode, the cumulative test time of each sample machine is T≥200h.
Note. For non-quick tests, the cut-off time can be determined based on the machine's daily work shift and the purpose of the test.
4.2.2 The tracking and statistical field test is adopted, and the cumulative test time of each sample machine is T≥2000h.
4.3 Censoring test
The requirements for the end of the test using the censored method are in accordance with relevant regulations.
5 Test requirements
5.1 Test environment
Room temperature.
5.2 Pre-test
5.2.1 Before the test, the machine tool shall be pre-inspected according to the requirements of the instruction manual or technical documents. After the machine has passed the pre-inspection, it can be carried out.
Rely on sex test.
5.2.2 Prior to the test, special handling of any quality aspects of the machine tool is not permitted.
5.3 Test equipment and instruments
5.3.1 The reliability test device used shall be safe and reliable and shall meet the test requirements.
5.3.2 The measuring instrument used shall be calibrated and within the calibration period.
5.4 Simulated field test
5.4.1 The actual working conditions of the machine tool should be simulated as much as possible.
5.4.2 The lubrication, cooling and other systems of the machine tool should be in normal working condition.
5.4.3 The test device should be placed in the middle of the workbench as much as possible and should be firm and reliable.
5.4.4 The toolies with the heaviest, longest and largest diameters should be installed in the tool magazine.
5.4.5 The test load spectrum and working condition spectrum shall be prepared according to the characteristics of the test machine.
5.4.6 When using a rapid test, the working principle of the machine tool, as well as the failure and failure mechanism should not be changed.
5.5 Tracking Statistics Field Test
5.5.1 The operating conditions of the machine tool shall be representative and conform to the product design or specification.
5.5.2 The selected prototype should be as similar as possible under similar operating conditions.
5.5.3 The machine tool shall be subjected to an early failure screening test.
5.5.4 All test machines shall have identification numbers.
5.6 Preventive maintenance
Normal preventive maintenance (if necessary replacement, adjustment, lubrication, etc.) is permitted during the test.
5.7 Failure Determination and Counting Principles
5.7.1 The principle of fault determination shall be in accordance with 4.1 of GB/T 23567.1-2009.
5.7.2 The counting principle of faults shall be in accordance with 4.2 of GB/T 23567.1-2009.
5.8 Sampling
5.8.1 The sampling principle shall be in accordance with 5.1 of GB/T 23567.1-2009.
5.8.2 The number of samples is randomly sampled in the product according to the sampling principle. The number of samples is as specified in Table 1.
Table 1 The sampling quantity unit is Taiwan
Test method
Number of samples
New product batch product
Simulated field test ≥1 ≥2
Field tracking statistical test -
Batch products ≤ 50, 5
(less than 5 by the number of units)
Batch products >50, for 10 or
5% of annual production, but no more than 20
6 Test methods
6.1 Simulated field test
6.1.1 Test content
The test contents of the machine tool simulation field test are shown in Table 2.
Table 2 List of machine tool simulation field test
Serial number test project test time test description
1 Dry running pre-run test ≥ 24h Dry running simulation test to eliminate early failure 6.1.2.1
2 X-axis loading test ≥ 40h Analog X-axis feed motion (such as milling) loading test 6.1.2.2
3 Y-axis loading test ≥ 40h Simulated Y-axis feed motion (such as milling) loading test 6.1.2.2
4 Z-axis loading test ≥ 40h Simulated Z-axis feed motion (eg drilling) loading test 6.1.2.2
5 Spindle system static stiffness test is used to analyze the reliability of manufacturing and assembly process 6.1.2.3
6 Spindle torque and power loading test ≥ 48h Analog spindle torque and power loading test 6.1.2.4
7 Typical test piece cutting test to verify the accuracy of machining accuracy 6.1.2.5
8 Enhanced air running test ≥24h
Mainly assessing tool change action, fast linear motion and spindle height
Reliability of speed swing, cooling, chip removal, etc.
6.1.2.6
9 Safety and reliability test
Mainly assess safety protection devices, hydraulic clamping devices, limits
Reliability of position limiting device
6.1.2.7
10 Machine tool accuracy inspection and inspection The accuracy change of each test stage is 6.1.2.8
6.1.2 Test procedure
6.1.2.1 Dry running test
6.1.2.1.1 CNC machine program according to GB/T 21012-2007, JB/T 8801-2017, JB/T 10793.3-2017 or enterprise
Conduct a dry run test.
6.1.2.1.2 The test time for the dry running of the machine tool shall be at least 24h.
6.1.2.1.3 During the test, the coolant should be turned on.
6.1.2.2 Axis loading test
6.1.2.2.1 Under the simulated working state, load tests are performed on the machine X axis, Y axis and Z axis respectively.
6.1.2.2.2 The loading force, loading time and loading frequency shall be in accordance with the provisions of the load spectrum.
6.1.2.2.3 Operating parameters such as spindle speed and feed rate shall be as specified in the operating spectrum.
6.1.2.2.4 The loading time for each axis shall be at least 40h.
6.1.2.3 Static stiffness test of spindle system
6.1.2.3.1 After each axis is loaded, the static stiffness test of the spindle system is carried out.
6.1.2.3.2 Under the simulated working condition, the static stiffness loading test shall be carried out on the machine tool spindle in the three directions of X, Y and Z respectively (see Figure 1).
6.1.2.3.3 The loading force shall not exceed the maximum load specified in the design.
6.1.2.3.4 The loading force in each direction shall be loaded in three gears (light load, medium load, heavy load), and the loading force of each gear shall be repeated three times.
6.1.2.3.5 Record the elastic displacement values of the main shaft in the X-axis, Y-axis and Z-axis directions, draw the corresponding elastic displacement curve, and calculate the main
The static stiffness of the shaft at maximum static load.
a) X, Y direction b) Z direction
Figure 1 Static stiffness test of the spindle system
6.1.2.4 Spindle torque and power loading test
6.1.2.4.1 In the simulated working state, the torque loading test is carried out under the low speed operation of the machine; the power loading is performed under the high speed operation of the machine tool.
test.
6.1.2.4.2 Loading force, loading time and loading frequency shall be as specified in the load spectrum.
6.1.2.4.3 Operating parameters such as spindle speed shall be as specified in the operating spectrum.
6.1.2.4.4 Torque loading and power loading time shall be at least 24h respectively.
6.1.2.5 Typical test piece cutting test
6.1.2.5.1 Test piece cutting test. The general machining center shall be in accordance with the provisions of GB/T 18400.7-2010, and the precision machining center shall be in accordance with GB/T 20957.7-
According to the regulations of.2007, the high-precision machining center is in accordance with JB/T 10793.1-2007 or JB/T 10793.2-2007, or according to enterprise standards.
According to the provisions of the technical specifications, the precision test of the typical test piece is performed on the prototype.
6.1.2.5.2 The number of processed test pieces shall be determined by the tester and the manufacturer in consultation.
6.1.2.6 Enhanced air run test
6.1.2.6.1 Intensify measures based on the content of the dry run test, the setting of the NC program shall include. the spindle adopts medium speed and high speed
Turn, increase the rapid movement of components and the high-speed running time of the spindle, increase the injection volume of the cooling liquid, increase the simulated cutting motion, and so on.
6.1.2.6.2 The idle test acceleration test time shall be at least 24h.
6.1.2.7 Safety test
6.1.2.7.1 Carry out relevant safety tests in accordance with the provisions of GB 5226.1-2008 and GB 18568-2001. Generally should include safety equipment
Tests such as setting, interlocking devices, control devices, moving parts, tool magazines, automatic exchange devices, and chip removal devices.
6.1.2.7.2 The number of machine tool safety tests shall be at least 20 times, and the functional safety test shall be at least 10 times.
The regulations are carried out.
6.1.2.8 Machine tool accuracy test
6.1.2.8.1 Geometric accuracy, positioning accuracy and repeat positioning shall be performed before the test, after each loading test phase, and after the end of the test.
Accuracy test.
6.1.2.8.2 Geometric accuracy test. Ordinary machining center according to GB/T 18400.1-2010 or GB/T 18400.2-2010, precision
According to GB/T 20957.1-2007 or GB/T 20957.2-2007, the high-precision machining center is according to JB/T 10793.1-
The provisions of.2007 or JB/T 10793.2-2007, or according to the standards of enterprises and technical specifications.
6.1.2.8.3 Positioning accuracy and repeat positioning accuracy test. Ordinary machining center according to GB/T 18400.4-2010, precision machining
According to the provisions of GB/T 20957.4-2007, the high-precision machining center is in accordance with JB/T 10793.1-2007 or JB/T 10793.2-2007.
Set, or according to corporate standards, technical specifications.
6.2 Tracking Statistics Field Test
6.2.1 Generally, on-site tracking should be carried out when the product is put into use.
6.2.2 After the test is stopped, the performance of the prototype and the main safety functions shall be checked.
7 Data collection and recording
7.1 Simulation field test
7.1.1 The operation of the machine should be checked at any time during the test and recorded (see Table A.1 in Appendix A). Records should be accurate, where changes are made
Wherever, there should be a record of the person’s signature and a reason.
7.1.2 In the event of a fault, immediately stop the inspection, the inspector immediately records each fault and fills in the “fault record form” (see
Table A.2) and the “Reliability Test Report” (see A.3).
7.1.3 During the test, the replacement of consumables and accessories that have reached the end of their life is not counted, but should be recorded.
7.2 Tracking statistics field test
7.2.1 Machine reliability field tracking test should have at least 2 data collection points.
7.2.2 Data collection may be performed by the tester or the organization user. When collecting data by users, the user should be trained to make the user clear
Meaning of meaning, master the method of fault recording, and provide the user with the fault record table and fault analysis report of the machine tool.
7.2.3 The tester should regularly visit the user's site to understand the situation and provide guidance on specific issues, and should record and report the user on a regular or one-time basis.
Responsible for recycling and responsible for saving.
8 Reliability assessment
8.1 Mean Time Between Failure MTBF Estimation
8.1.1 Mean time between failures The MTBF estimation is calculated as specified in equation (1).
MTBF=
K∑
j=1
Tj
1 (∑
j=1
Rg)2 (∑
j=1
Rs)
(1)
In the formula.
k --- reliability factor;
Tj --- The cumulative working time of the jth machine in the assessment period, in hours (h);
Rgj --- The number of effective cumulative function failures of the jth machine tool in the evaluation period, in units;
Rsj --- The cumulative failure of the jth machine tool in the assessment period, in units of one;
n --- The number of prototypes, the unit is Taiwan.
8.1.2 The reliability factor k shall comply with the provisions of B.1 of Appendix B.
8.1.3 The number of failures rsj shall comply with the provisions of B.2.
8.2 Evaluation of reliability test results
It shall be carried out in accordance with the provisions of Chapter 12 of GB/T 23567.1-2009.
Appendix A
(informative appendix)
Reliability test record
A.1 Reliability test operation record
The machine reliability test operation record is shown in Table A.1.
Table A.1 Machine Reliability Test Operation Record Table
(stamp)
Product Name Product Model Factory Number
Manufacturing unit date
Test date. year, month, day, year to month
Test Location
Run date shift
Machine running time fault repair time
Start and finish repairing
Number of failures
recorder
signature
Cumulative running time/h cumulative repair time/h cumulative faults /
Note. Fill out a form for each product and the form can be continued.
A.2 Reliability test failure record
The machine reliability test failure record is shown in Table A.2.
Table A.2 Machine Reliability Test Fault Record Table
(stamp)
Product Name Product Model Factory Number
Manufacturing unit date
Fault discovery time year, month, day and hour
Fault repair time, year, month and day
Site conditions
Fault location
Spindle □ Lead screw □ Guide □ Feed system □ Turntable □
Pallet □ Tool magazine □ Tool changer □ CNC system □ Servo unit □
Motor □ Electrical System □ Hydraulic System □ Pneumatic System □ Lubrication System □
Cooling system □ Tool □ Other □
Fault phenomenon
cause of issue
Fault repair measures
Tester (signature) Fill in the date of the date
Fill in the form (signature) Fill in the date of the date
Note. Fill out a form for each product and the form can be continued.
A.3 Reliability Test Report
The model of the machine reliability test report is shown in Table A.3.
Table A.3 Machine reliability test report style
Cover
Number. ××××
Reliability test report
Machine model. Machine name.
Factory number. Production date.
Company Name.
Written. Year Month Day
Review. Year Month Day
Approval. Year Month Day
××××unit
Table A.3 (continued)
experiment report
Report No.. Total × Page × Page
Test unit
Question number name
Product Name Inspection Category
Model prototype number
Sample grade sample quantity
Production date inspection date year, month, day to year
Test site tester
Test basis
2.××××-××××××××××××
The standard (and the project contract), the reliability test was carried out on the ×××× machining center, and the test results are detailed in the summary table.
According to the test results, the expected MTBF of the machine tool reliability is ××h.
Official seal
Or a special chapter for the test report
××××year××month×× day
Remarks (blank)
Table A.3 (continued)
Test report content
(slightly)
Appendix B
(normative appendix)
Reliability coefficient k and number of failures rs
B.1 Reliability coefficient k
B.1.1 Calculation of reliability coefficient k
The reliability coefficient k is calculated as specified in equation (B.1).
k=kz·ks·kq (B.1)
In the formula.
Kz---manufacturing coefficient;
Ks---test coefficient;
Kq---enhancement coefficient.
B.1.2 Reliability Manufacturing Factor kz
B.1.2.1 The reliability manufacturing factor kz is calculated according to the formula (B.2).
Kz=kz1·kz2·kz3 (B.2)
In the formula.
Kz1---CNC axis coefficient;
Kz2---assembly coefficient;
Kz3---assembly environment factor.
B.1.2.2 The reliability manufacturing factor kz is selected in accordance with Table B.1.
Table B.1 Reliability Manufacturing Factor kz
Numerical control axis coefficient
Kz1
Assembly factor
Kz2
Assembly environment factor
Kz3
0.91~1.20 0.95~1.04 0.97~1.05
B.1.3 Reliability test coefficient ks
B.1.3.1 The calculation of ks is as specified in equation (B.3).
Ks=ks1·ks2·ks3·ks4·ks5·ks6 (B.3)
In the formula.
Ks1---force load factor;
Ks2---torque load factor;
Ks3---loading time factor;
Ks4---spindle speed coefficient;
Ks5---spindle start and stop coefficient;
Ks6---Changing frequency factor.
B.1.3.2 The reliability test coefficient ks is selected in accordance with Table B.2.
Table B.2 Reliability test coefficient ks
Force load factor
Ks1
Torque load factor
Ks2
Load time factor
Ks3
Spindle speed coefficient
Ks4
Spindle start and stop coefficient
Ks5
Tool change frequency coefficient
Ks6
1.42~1.52 1.17~1.19 0.97~1.10 0.87~1.22 1.42~1.52 1.01~1.10
B.1.4 Reliability enhancement coefficient kq
The reliability enhancement coefficient kq is set to 5.3.
B.2 Failure number rs
B.2.1 Calculation of the number of failures rs
The calculation of the number of failures rs is as specified in equation (B.4).
Rs=0.25rs1 0.25rs2 0.15rs3 0.20rs4 0.15rs5 (B.4)
In the formula.
Rs1--- geometric accuracy failure;
Rs2---...
Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 23567.2-2018_English be delivered?Answer: Upon your order, we will start to translate GB/T 23567.2-2018_English as soon as possible, and keep you informed of the progress. The lead time is typically 2 ~ 4 working days. The lengthier the document the longer the lead time. Question 2: Can I share the purchased PDF of GB/T 23567.2-2018_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 23567.2-2018_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to [email protected]. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.
|