Does anyone know if there is a difference in the JIS standard and the ISO standard on thread size. Here is the problem. I have a M14 X 1.50 6g thread ring checking a bolt that is suppose to be that size from a vendor. The NOGO thread ring will thread all the way on the bolts. The vendor is saying that they have to go by the JIS standard whereas my thread ring and master gage is certified to ISO standards. They are saying that is the problem. The way I look at it is that M14 x 1.50 6g NOGO should be 12.854 no matter what standard.
Sorry Dale, when it comes to standards one can never assume equality from one standards board to another. Your statement begs two questions.
1. To which JIS standard is your supplier’s gage certified? JIS B 0252 or JIS B 0251 (Class I or Class II)
2 To which standard are your gages certified? Given your location is Arkansas, unless you made special provisions at time of purchase, I assume that they are made to ANSI standards.
Regardless of which JIS standard your supplier is using for his gages, and assuming that your gages are made to ANSI standard, it is totally possible that your NOGO gage will screw all the way on a bolt which has been deemed acceptable by a JIS NOGO ring gage. Of course, this statement begs the question: Why?
The standards that define the common M-profile, metric, 60 Degree form thread are:
ISO 965-1:1998 Metric Screw Threads-Principles & Basic Data
ISO 965-2:1998 Metric Screw Threads-Limits of Sizes
BS ISO 965-1:1998 Metric Screw Threads-Principles & Basic Data
BS ISO 965-2:1998 Metric Screw Threads-Limits of Sizes
BS 3643-1:1981 ISO Metric Screw Threads-Principles & Basic Data
BS 3643-2:1981 ISO Metric Screw Threads-Specification for Selected Limits of Sizes
JIS B 0209 Metric Screw Threads
DIN 13 (this standard has multiple parts)
ANSI/ASME B1.13M:2001 Metric Screw Threads M Profile
All of the above standards for M-profile metric threads are technically equivalent. By this it is meant that the threads defined in each standard are the same as the threads defined in any of the listed standards.
Editorial note: The BS 3643 and the DIN 13 should be considered obsolete. Manufacturers interested in selling to the European Community (EC) marketplace should move toward the ISO 965 with all due haste because it is the accepted standard for the entire EC. Because the standards are technically equivalent, moving toward the standard only requires changing drawing notations, catalogs and advertising literature to reference the ISO 965 and eliminate reference to any of the obsolete standards.
We will use M14x1.5 as the thread size example. We will discuss the 6g external class-of-fit and the 6H internal class-of-fit because they are the most commonly used class-of-fit. For JIS B 0209 we will discuss class II. For this thread, all of the above standards identify the following size data:
M14x1.5-6g External Thread
Major Diameters as: 13.968/13.732mm
Pitch Diameters as: 12.994/12.854mm
Minor Diameter as: 11.930mm minimum
M14x1.5-6H Internal Thread
Major Diameter as: 14.000mm maximum
Pitch Diameters as: 13.216/13.026mm
Minor Diameters as: 12.676/12.376mm
So far all standards agree; however; the water gets murky when we evaluate the gage standards.
The standards that define the gages used to measure the metric (M) thread are:
ISO 1502:1996
BS 919-3:1968
JIS B 0252:
DIN 13/16, /17 & /18
ANSI/ASME B1.16M:1984 Gages/Gaging for Metric Screw Threads
JIS B 0251:1975 Metric Screw Threads-Gauging
The standards are not all identical. The first four listed above are technically equivalent. The last two differ from the first four and from each other. To view the differences between each of the standards view the attached chart at the bottom of this post. The differences only cause a problem if the product is manufactured near the product limits. A product made to the mean will be passed by all gage systems.
I think that the chart makes it clear that all gages are not created equally. The chart also emphasizes the importance of specifying not only the product specification but also the gage specification to be used when evaluating a product.
For the record, and some boring reading, the individual features of the gages are delineated below.
GO and NOGO Ring Gages Major Diameters:
ISO 1502 = 13.968mm minimum
BS 919-3 = 13.968mm minimum
JIS B 0252 = 13.968mm minimum
DIN 13 = 13.968mm minimum
B1.16M = 13.968mm minimum
JIS B 0251= not stated
GO Ring Gage Pitch Diameters:
ISO 1502 = 12.995/12.977mm
BS 919-3 = 12.995/12.977mm
JIS B 0252 = 12.995/12.977mm
DIN 13 = 12.995/12.977mm
B1.16M = 12.994/12.986mm
JIS B 0251:GRII = 12.981/12.971mm
NOGO Ring Gage Pitch Diameters:
ISO 1502 = 12.854/12.836mm
BS 919-3 = 12.854/12.836mm
JIS B 0252 = 12.854/12.836mm
DIN 13 = 12.854/12.836mm
B1.16M = 12.862/12.854mm
JIS B 0251:IRII = 12.856/12.846mm
GO Ring Gage Minor Diameters:
ISO 1502 = 12.353/12.335mm
BS 919-3 = 12.353/12.335mm
JIS B 0252 = 12.353/12.335mm
DIN 13 = 12.353/12.335mm
B1.16M = 12.344/12.329mm
JIS B 0251:GRII = 12.336/12.320mm
NOGO Ring Gage Minor Diameters:
ISO 1502 = 12.554/12.518mm
BS 919-3 = 12.554/12.518mm
JIS B 0252 = 12.554/12.518mm
DIN 13 = 12.554/12.518mm
B1.16M = 12.554/12.569mm
JIS B 0251:IRII = 12.420mm no tolerance specified
GO Plug Gage Major Diameters:
ISO 1502 = 14.023/14.001mm
BS 919-3 = 14.023/14.001mm
JIS B 0252 = 14.023/14.001mm
DIN 13 = 14.023/14.001mm
B1.16M = 14.015/14.000mm
JIS B 0251:GPII = 14.024/14.008mm
NOGO Plug Gage Major Diameters:
ISO 1502 = 13.5325/13.5215mm
BS 919-3 = 13.5325/13.5215mm
JIS B 0252 = 13.5325/13.5215mm
DIN 13 = 13.5325/13.5215mm
B1.16M = 13.516/13.501mm
JIS B 0251:IPII = 13.610mm no tolerance specified
GO Plug Gage Pitch Diameters:
ISO 1502 = 13.0435/13.0325mm
BS 919-3 = 13.0435/13.0325mm
JIS B 0252 = 13.0435/13.0325mm
DIN 13 = 13.0435/13.0325mm
B1.16M = 13.034/13.026mm
JIS B 0251:GPII = 13.041/13.031mm
NOGO Plug Gage Pitch Diameters:
ISO 1502 = 13.227/13.216mm
BS 919-3 = 13.227/13.216mm
JIS B 0252 = 13.227/13.216mm
DIN 13 = 13.227/13.216mm
B1.16M = 13.216/12.208mm
JIS B 0251:IPII = 13.186/13.176mm
GO and NOGO Plug Gages Minor Diameters:
ISO 1502 = 12.376mm maximum
BS 919-3 = 12.376mm maximum
JIS B 0252 = 12.376mm maximum
DIN 13 = 12.376mm maximum
B1.16M = 12.376mm maximum
JIS B 0251= not stated
