Variable Thread Gages

SYSTEM 21A (FOR METRIC THREADS IN ACCORDANCE WITH ANSI B1.18M)
System 21A provides for interchangeable assembly with functional size verified at the maximum material limit using standard length gaging elements. This can be accomplished using fixed limit gaging or variable gaging with functional elements. System 21A also states that the minimum material limit (minimum pitch diameter) must be verified by inspecting two thread flank locations over the length of the thread. This can be accomplished by using variable gaging or thread roll snap gages with pitch diameter elements.

SYSTEM 22
System 22 provides for the interchangeable assembly with functional size verified at the maximum material limit using standard length gaging elements. This can be accomplished using fixed limit gaging or variable gaging with functional diameter elements. System 22 also states that the minimum material limit (minimum pitch diameter) must be verified over the full length of the thread. This can be accomplished using variable gaging with pitch diameter elements.

SYSTEM 23
System 23 provides for interchangeable assembly with functional size verified at the maximum material limit using standard length gaging elements and minimum material limit (minimum pitch diameter) must be verified over the full length of the thread. The gaging requirements for SYSTEM 22 would also apply here but in SYSTEM 23 other thread characteristics such as lead, flank angles, taper and roundness must have to be independently verified. Only thread characteristics, which are specified, will have to be inspected for SYSTEM 23 compliance.

Precision
Ball slide construction and constant gaging pressure assure precise reading through linear travel of the ball slide.

Definitive
Helical path seating and 60% peripheral contact provide functional size position within the pitch diameter tolerance assigned.

Gaging Range
Single frame covers a size range of #10 through 3/4”.

Versatile
Segments are easily changed with positive mounting pin alignment.

Economical
Reduced gaging time compared to Go/NoGo gages .

Precision
Rigid construction and constant gaging pressure assure precise readings.

Definitive
The ITC reads the actual size of the pitch diameter showing its position in relation to the pitch diameter tolerance assigned.

Gaging Range
Single frame covers a size range of #10 through 2 1/2” , Larger frames are available up to 8”

Versatile
The positive alignment feature of the frame allows segments to be easily changed with positive mounting pin alignment.

Economical
Reduced gaging time compared to Go/NoGo gages .

 

Available with digital read out and RS232 outputs.

Rigid construction and constant gage pressure guarantee consistent and precise readings.

• Qualitative Readings

The Tri-Roll not only indicates whether a threaded part is within assigned limits, it also shows the exact position of the pitch diameter within a tolerance range. In addition, the Tri-Roll will check size and out of roundness of plain cylindrical parts.

• Repeatability
Fixed mounting of the lower rolls assures a solid support for the work piece. Only the upper roll actuates the indicator, thereby providing repeatable readings.

• Easy to Set
No adjustment required on the lower rolls means that no adjustment is required when changing from one thread size to another.

• Wide Gaging Range
Both the ITC and the Tri-Roll are able to inspect a wide range of parts with a single frame.

• Adaptability
The variable thread system can be used to measure plain diameters and can be used with the “Zero Spindle “ gage system. Economical with Long Work Life The variable thread gage system provides longer life of the tooling and thus reduces cost.

Full ribbed rolls for functional sizes coarser than 48 T.P.I (For 48 T.P.I and finer the ribs locate on alternate threads)

Two ribs (“vee type”) on lower rolls (1 and 3) One rib (“cone type”) on upper roll (2) Flank contact limited

Single ribs only with “Best Wire” sizeradius for any given pitch (T.P.I)

Straight cylindrical rolls for checking diameter and out of roundness.

(55° included angle) Two full profile “vee” rolls (1 and 3) and one full profile cone roll (2)

Two full profile “vee rolls (1 and 3) with outside flanks relieved. and one full profile cone roll (2)