Bs 3643comprises two parts.
Thread ring gauge after plating.
For external threads class 6e may be used as a pre plating condition for 6g after plating.
Before plate or pre plate thread plug gauges when you need to leave extra room for plating.
Then subtract the minimum plating from the p d.
Limits for 6g before coating or plating.
After the threaded parts are coated or plated they must be inspected using the 6h go thread limits and gages and the 6g nogo limits and gages for inspec tion and acceptance.
Ideally the screw or.
After plating the internal threads need to pass the inspections of a standard m13 2 0 3 6h plug gauge.
Iso metric plug ring and caliper thread gauges gauges for testing iso metric screw threads to bs 3643 1981 and bs 919 pt 3 1968.
Do you need a specialty thread ring gauge.
To determine pre plating dimensions for thread ring gages.
As a pre plating condition for 6h after plating.
On not go thread rings decrease the minor diameter by using half the min.
It may be a good idea to supply the plating facility with these gages so they can confirm that their plating process is correct and deliver back parts that are in tolerance.
For the minors of thread rings decrease the minor diameter on the go thread ring by using half the max.
This can be confirmed with standard or after plate thread gages.
The go and no go rings are normally separate pieces.
Of the go thread ring gage.
For thread ring gages subtract the max plating thickness from the p d.
Specialty thread ring gauges.
One threaded end is 1 4 inch and the other 3 4 inch.
A thread ring gauge is designed to check the correctness of the thread to include thread depth and pitch diameter to the given pitch tpi.
Whether you need a specialty taperlock plug gauge aka work plug gauge or a specialty trilock plug gauge we can make what you need and turn around the order quickly.
For the minor diameter reduce the go ring minor diameter by half the maximum plating and reduce the no go.
Before plating appropriate sample size passed qc ring gauge inspection.
Of the no go thread ring gage.
Once they pass the inspection they can be approved for shipment.
For acceptance of the part the go ring gauge should pass through the entire length of the screw without too much use of force.
Example for thread ring gages.
Plating of 0002 0003 allowance per side multiple x 4 0003 x 4.
Parts are 2 inches long with 1 inch hex between the 2 10 32 threaded ends.
If there is an external thread on the plated component after cnc processing the pre plated ring gauge inspection will be necessary.
This means that the class 6g go and 6g nogo limits and gages must be used to inspect and accept the before coated or plated threads.
Class 6g may also.
After plating about 40 of studs at the short end either strip out when the nut is applied or strip the nut itself out.