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New Chamfer Gage

Chamfer Gage

Thread Check offers the GSG chamfer gage which is an innovative easy to use gage for accurately measuring chamfers. The indicator features a hard programmed ratio measuring mode which accurately calculates the chamfer size. The instrument includes one digital indicator, 1 collet assembly, 1 attachment housing and 1 thumb ring. Individual anvils and chamfer ring masters are offered in a wide range of standard and custom sizes. 3 Piece chamfer gage sets in 3 lengths and 4 included angle sizes are also available. Anvils are offered in standard sizes of 62°, 92°, 120°, and 135° as well as custom angles priced on request. The lengths include 2.0”, 4.0” and 6.0”.

Chamfer master ring gages are available in A2 steel and carbide. Chamfer master ring gages are supplied in class X tolerance and include a long form calibration report


New Thread Check Catalog

Thread Check Inc., is proud to announce the release of our 2016 Precision Gage Solutions catalog with over 180 pages of precision gages, measuring instruments and technical information. Our new catalog is available for download or in an electronic book format for easy use. The new catalog has links to where our customers can shop on line, request quotes and view hundreds of technical articles. Use the table of contents to quickly turn to the product selection of your choice. Use electronic book marks for the pages you visit frequently. The new electronic catalog works across all platforms including tables and smart phones.

Thread Check Catalog 2016 Cover




How to Use Thread Ring Gages

Go and no go thread ring gages are very easy to use. The user must first select the correct size thread ring gages for the corresponding externally threaded product. This is obviously critical but sometimes difficult as drawings and specification requirements are frequently missing, incomplete, or incorrect. The user of the thread ring gages should ensure that the correct major diameter, TPI/pitch, Class of fit, and any special pitch diameters are clearly specified. The user should also confirm that the gages conform to the proper national or international standard. In the USA it is commonly assumed that metric thread gages conform to the ANSI/ASME B1.16M but this may not be the case particularly when working with an international customer or a globally recognized company with manufacturing facilities located in the USA and engineering located in Asia or Europe. Other metric standards like ISO or JIS may be required. It is also important to confirm that pitch diameters on the gages match the part specification. For example a part gaged prior to plating will have special pitch diameters. The thread ring gages selected should be engineered and made correctly to the preplate or before plate pitch diameters. The thread ring gages should be marked with B/P or P/P designation for quick and easy identification. Finally the inspector should confirm the gages are calibrated. It is always advisable to recheck the thread ring gages prior to use with the matching set plug regardless of the calibration sticker’s current status. Many companies arbitrarily select annual frequencies of calibration rather than basing frequency on usage. This can be dangerous as thread ring gages can be worn out of tolerance or damaged during the course of a production run. The best thread ring gaging practice utilizes several sets of thread ring gages all set to a matching master set plug gage. One or two sets can be used for in process inspection while another set can be used for final inspection and a master set retained for dispute in the event that gages fail to correlate.

Adjustable American Gage Design - AGD thread ring gages are designed with radial slots which form natural dirt grooves that tend to clean the threads of the work piece. It is important to note that thread ring gages are not work dies. It is advisable to clean the work piece prior to gauging as this will extend the wear life of the thread ring gages. Thread ring gages should be cleaned with solvent or air and then frequently recoated with a rust preventative/gage preservative. Thread ring gages should be laid flat to prevent them from rolling off a table. All gauging whenever possible should be done over an inspection table in the event that the gage is accidentally dropped. If a gage is dropped it should be immediately re-inspected with a matching set plug. Any impact to the thread ring gages may result in a change to its size.

The go thread ring gage should engage the externally threaded part with very little force used. The engagement should be smooth. There is no specification regarding torque or pounds of pressure for using thread ring gages. Common sense should be applied based on factors of thread size, pitch, and application. If the gage starts to bind, the inspector should stop before damaging the part or the gage.  The part may be oversized or tapered. Other possibilities include lead error or a damaged thread. An inspector can evaluate the critical elements of the threaded part by inspecting the major diameter using a measuring instrument such as a micrometer. Pitch diameter may be checked by using a 3-wire method. Lead, angle and minor diameter can be checked with an optical comparator or vision system. With fine threads the inspector should be careful to not cross thread the parts.

It is important to use the no go gage as it checks pitch diameter exclusively. It is unaffected by other conditions in the screw thread as it is intentionally truncated on the crests and with greater clearance applied on the roots of the thread. The no go thread plug should not enter the part more than 3 turns although in practice it is advisable to limit the amount of turns to 1 ½ - 2 turns max. The user just simply counts turns. The end user should review the applicable thread specification in detail as there are variations to the above practice.

Thread Check Inc.


Adjustable Limit Snap Gages

Adjustable limit snap gages provide a quick and easy attribute method of checking outside diameters, groove diameters, or width dimensions by having the go and no go elements set into the snap gage. Thread Check offers 4 assorted frame styles of snap gages with sizes ranging up to 8 5/8. Larger frame sizes are quoted upon request. The anvil gaging contacts on the snap gages are adjustable and can be set to various sizes within a range. The anvil gaging surfaces are made of hardened ground and lapped tool steel. Marking discs are supplied on all snap gages. Thread Check’s standard snap gages are progressive in design. The work piece should enter the go limit and stop at the no go limit which is towards the back. Other designs are double ended and single purpose snap gages.

The snap gage works like a fixed caliper once it has been adjusted and set to a maximum and minimum size limit. To use a snap gage the upper anvil should be used as a reference point on the work piece. The gage should be pivoted with the upper anvil acting like a hinge and the lower anvil gaging the work piece. The plane of the snap gage should be perpendicular to the centerline of the work piece. The user must be careful not to tip or angle the snap gage which could create a false measurement. Care should be taken to use gentle force when gaging work pieces with snap gages. Snap gages can be used to gauge work pieces still loaded in a machine or hand held at an inspection area. Snap gages can also be mounted in stands so that an inspector can use both hands to manage the work piece.

Specifications for Thread Check Adjustable Limit Snap Gages

Adjustable Limit Snap Gages


Frame Description:

  • Model A Style 104:
    Covering: Metric Range: 0-229mm / Inch Range: 0-9
    Has 4 plain cylindrical pins in hardened tool steel. All 4 pins are adjustable for maximum working range.
    Maximum parallelism error over adjustment range 0.005mm (frame size 1-6) or 0.008mm (frame 1-13X).
  • Model C Style 108:
    Covering: Metric Range: 0-219mm / Inch Range: 0-8.5/8
    Has a rectangular plate anvil and two opposing square headed anvils  - all in hardened tool steel.
    These gauges have the largest gauging surfaces and hence longest life.
    Maximum parallelism error over adjustment range 0.005mm (frame size 1-6X) or 0.008mm (frame 7-13X).
  • Model MC Style 102:
    Covering: Inch Range 000 - .760"
    Has a one peice rectangular anvil and two adjustable square anvils - all in hardened tool steel.
    These gauges have the largest gauging surfaces and hence longest life.
    Maximum parallelism error over adjustment range 0.005mm (frame size 00 - 0 ).
  • Model U:
    Covering: Metric Range: 0-210mm / Inch Range: 0-8.1/4
    Has knife edge anvils and is based upon the C Type frame - steel only.
    These are typically used for measuring external grooves.
    Standard anvil width and depth 2.4 x 4.7mm.
    Miniature range anvils are 0.8 wide x 2mm deep.

For more information to purchase snap gages contact Thread Check Inc.

631 231 1515


Gage Certification

Thread Check Inc offers 3 different levels of certification for all gages

1.       Certificate of Compliance (  C of C )

Is a general statement that the gages have been manufactured and are in conformance to the applicable gage specification. The Certificate of Compliance states that the gages have been manufactured and inspected by highly trained personnel and found to comply with the dimensions and tolerances specified. The Certificate of Compliance states that the primary reference standards for the gage calibration are traceable to System International (S.I.) units through the N.I.S. T - National Institute of Standards and Technology. The N.I.S.T. number referenced on this cert is being phased out by the requirements of A2LA. The Certificate of Compliance also states that the gages are inspected in compliance with MIL-STD 45662A, ISO 10012-1, and ANSI/NCSL Z540-1.

The Certificate of Conformance supplied by Thread Check Inc. conforms to the standard scope adopted by the American Measuring Tool Manufacturers Association – AMTMA. It is neither a contract nor a contractual representation.  The Certificate of Conformance states that the company’s responsibilities shall in no event nor for any cause what so ever, exceed the purchase price of the pertinent gage(s).





Thread Check Inc. offers a manufacturing Long Form Calibration which provides all the critical gage dimensions and tolerances for the applicable standard. The Manufacturer’s Long Form Calibration demonstrates that the gages have been manufactured and inspected by highly trained personnel and found to comply with the dimensions and tolerances specified in the applicable standard. Long Form Calibration reports for thread gages list Pitch diameters, major diameters, minor diameters, lead, and angles. Long Form Calibration for Plain gages typically list measurements in 3 places. Thread Check does not provide calibration stickers on new gages.

Thread Check Inc. does not issue calibration frequencies on new gages.

Thread Check Inc. does not issue IDs or serial numbers unless specified by the customer.

Thread Check Inc. can supply a serial number at no additional charge if requested by the customer.






Thread Check Inc. sends the gages to a third party calibration lab that is ISO 17025 accredited. The lab is ACLASS accredited. All critical dimensions are listed on the calibration cert. The laboratory is accredited in accordance with the recognized International Standard ISO/IEC 17025:2005. This accreditation demonstrates technical competence for a defined scope and the operation of a laboratory quality management system (refer to joint ISO-ILAC-IAF Communiqué dated January 2009).



Gagemaker Ball Pitch Diameter Gages

Thread Check offers a wide range of pitch diameter gages manufactured by Gagemaker. These types of gages are commonly known as ball PD gages as they accurately measure pitch diameter which is one of the most important characteristics of a thread. Pitch diameter represent the widest spectrum of potential defects on a screw thread. Improperly sizes pitch diameters compromise the load capacity of your threaded components.

Gagemaker uses contact point (or contact ball) gages to inspect lead, taper, height, and pitch diameter on nearly any type of thread. Generally, these gages require two contact
points. Our points are inter-changeable; one set of points often can be used on different types of inspection gages. For best results, we still recommend one set of points for each gage.
Gagemaker offers spherical points and truncated points to measure pitch diameters. Truncated points as illustrated ensure contact on the flanks of the thread pitch line and eliminate the possibility of bottoming out on the root or minor diameter of the thread.

truncated points are used to measure pitch diameters of certain straight threads, primarily Acme, Stub Acme, and the modified Stub Acme threads.

Spherical points are commonly used for *UN Series, Metric, 7x45 Buttress, and nearly all tapered threads (tubing & casing and rotary shouldered connections).

Note: Remember when setting a gage with truncated points set on the truncated surface of the point. Gagemaker will provide set-to-flat value to compensate for the truncation.

Gagemaker Ball Pitch Diameter Gages

Gagemaker Ball Pitch Diameter GagesGagemaker Thread Gages


Gage Makers’ Tolerances

Gage Makers tolerances have been established by the American Gage Design Commitee and are referenced for building and calibrating all solid ring gages, plug gages, and fixed snap gages. Gage Maker tolerances are refered to as classes. For example Class ZZ tolerance is an open tolerance or economical tolerance. There are 6 classes of tolerance - class XXX, XX, X, Y, Z, and ZZ.

See the link below for Gage Maker tolerances in inch and metric




Measuring Plain External Diameters – American vs European

A case related to pin gages being rejected by our European Customer

The ASME B89.1.5-1998 is the correct document to review. Reference para. 6.1, pg. 5 & 6 as well as Table 4 on pg. 7. The values were computed using the equation in Puttock and Thwaite’s CSIRO Technical Paper #25. This statement is also on page 6. The question that should be asked is, what is their measurement uncertainty? Remember that the Europeans add measurement uncertainty into their measurements. We do not do that in the US. Depending on the uncertainty budget, they may not have the accuracy to measure a .000020” gage. Our measurement uncertainty is .000012” based on our latest accredited calculations . This is not good enough to accurately measure a Class XX pin. Our customers accept our measurements as long as our uncertainty is stated on the calibration certificates. According to ANSI/NCSL Z540 & ISO 17025 the total uncertainty of the measurement should not exceed 4:1. That would require a total measurement uncertainty of .000005”. The only lab that I know of that can measure this accurately w/in the 4:1 Rule, and prove it, is NIST.

See the link to the NIST web site that has a calculator to assist in the measuring force calculation.

Note: The measuring force changes with the diameter of the part being inspected.


Thread Check Inc now offers a complete line of high precision feeler gauges

high precision feeler gaugesOur feeler gauges are widely used by many industries as gages to precisely measure clearances and gaps in machinery, dies, and component parts and as shims to accurately set spacing. They can be supplied in thicknesses ranging from .0005” up to .125” in various lengths and widths. They are conveniently available in 6" and 12" strips, 25' coils, as well as standard and custom blade sets. Our steel blades are offered in the highest quality carbon steel or stainless steel for outstanding resistance to corrosion and all blades are permanently marked with the thickness size for easy identification. The standard tolerance on all blades is +/- .0005" (+/-.0127mm). Tighter thickness tolerances of +/- .0001” are available if required. We also offer custom bending and stamping solutions to design a way around obstructions. The option of adding a step creates two gauges in one and can be used as a Go/No-Go gauge or for different applications. We commonly provide air gap gages for power and utility companies in 24", 36", and 48" lengths

Feeler Gauges are a close relative to plug gages.  One of the most common applications of a feeler gage is for use with spark plugs on engines to establish the gap between the distributor points. Feeler gauges of 24", 36", and 48" lengths are also used by power and utility companies  to inspect air gaps in their equipment. Stainless Steel feeler gauges are commonly used to check critical medical dimensional characteristics.

Feeler Gages



How to determine the proper gagemaker tolerance for a GO/NO GO cylindrical gaging application.

One of our most frequently asked question is “Which gagemaker class of tolerance should be used for selecting plain plug and ring gages to check internal and external diameters of parts?”

The industry standard is referred to as the Ten Percent Rule. This common rule of practice requires that 10% of the product tolerance is divided between the GO and NO GO gauges. For plug gages a plus tolerance is applied to the GO member and a minus tolerance is applied to the No Go member. Ring Gauges receive the reverse tolerance direction so that the GO member is minus and the NO GO member is plus.

10 Percent Rule results in gauge tolerance always being included in the part tolerance by up to 10%. This rule results in the possibility that 10% of good product may fail inspection but that no bad product would ever pass inspection.


A part has a hole diameter requirement of .500” +/- .001”. Thus the hole diameter is .4990” - .5010”. The product has a tolerance of .002”. 10% of the product tolerance is .0002”. Divide .0002” by 2 = .0001”. On the industry standard gagemaker chart, .0001” is classified as a class Z tolerance.  The Go member would be specified as .4990” plus .0001” tolerance and the No Go would be specified as .5010”minus .0001”. The gage would be assembled and marked as .4990”- .5010” Class Z Go/No Go Plug Gage w/handle.

Selecting higher precision gagemaker tolerances for cylindrical plug and ring gages such as class X or XX will consume less product tolerance and will allow the acceptance of slightly more product but with less gage wear life and at greater expense.

Thread Check’s engineering staff can make recommendations in selecting the correct gagemaker tolerances for a given application.

Gage maker Chart

Gagemaker Fact Sheet

View our complete product listing of cylindrical products here