In Gage Threadcheck's Official Blog

21Jul/160

Thread Check ISO Certification Audit

We are pleased to announce that Thread Check Inc. passed its 2016 ISO 9001:2008 Audit with a perfect score.

ABS Quality Evaluations conducted a full 1 day audit of Thread Check' quality management system. There were no major or minor non conformities found during the audit. This is the 7th year in row with zero nonconformities. This is a testament to our organization's continued commitment to customer satisfaction, employee empowerment and continuous improvement.

I would like to thank and congratulate all of our employees for their commitment to the quality management system.

Thread Check Inc. is now planning on implementing ISO 9001: 2015 for the coming year.

23Jun/16Off

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 www.threadcheck.com 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.

http://user-CfZTcuf.cld.bz/Thread-Check-Inc-Catalog-2016

Thread Check Catalog 2016 Cover

 

 

22Jun/16Off

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. http://www.threadcheck.com/no-go-gaging-per-ansi-asme-b1.2-1983-an-american-national-standard/technicalinfo/.

Thread Check Inc.
info@threadcheck.com
www.threadcheck.com
631-231-1515

26Apr/16Off

Root Relief in Thread Ring Gages

All Thread Check Inc. thread ring gages are root relieved for longer gage life and more accurate gaging. Thread ring gages are manufactured with a root clearance in the major diameter which eliminates the possibility of interference from the full form section of the thread setting plug and major diameter of the part being gaged. This critical feature assures that the thread flanks are making proper contact.

http://www.threadcheck.com/0-80-unf-2a-go-ring-gage/unified-inch-thread-gages/
http://www.threadcheck.com/m16-x-35-6g-go-thread-ring-gage/unified-metric-thread-gages/
14Mar/16Off

STI Helical Coil Thread Gages

STI helical coil thread gages are used to gage tapped threaded holes prior to installing screw thread inserts. Screw thread inserts are used to provide stronger thread assembly or to repair a damaged thread.

If the tapped hole gages correctly then it is not necessary to gage the installed insert. The go thread plug may not enter freely after the insert is installed. A properly manufactured insert will always seat itself when the bolt and screw is installed and tightened.

The no go gage should not enter more than 3 turns. Tapped holes should be thoroughly cleaned prior to gaging.

STI gages are manufactured to class X tolerances. W tolerance plug gages are priced on request.

Thread plug gages are manufactured of oil hardened tool steel. Thread Check Inc. offers chrome plated STI thread plug gages which can extend the wear life of the gage by more than 100% thus providing dramatic savings on replacement cost.

STI thread gages are avialable in unified, metric, and special sizes.

http://www.threadcheck.com/2-56-unc-2b-sti-go-nogo-thread-plug-gage-w-handle-class-x/thread-gages-gauges/

sti-thread-plug-gages

www.threadcheck.com
info@threadcheck.com
631 231 1515

8Feb/16Off

Air Gaging

For very tight tolerance dimensions, air gaging is a proven inspection tool that allows for measurements to be made faster, more accurately and more conveniently than other gaging methods. Air gages are unsurpassed for speed and accuracy in measuring tight tolerance holes. For checking other dimensional features; air gages offer sufficient magnification and reliability to measure tolerances typically beyond the capability of mechanical and fixed limit gages.

There is no special training required for production workers to use air gages. No special techniques are required like with certain types of fixed limit gaging. The inspector simply inserts the air plug in the hole or air ring onto the shaft and reads the meter.

Air gaging is economical and versatile. After the initial purchase of the gage system, additional gage tooling can be purchased for a wide variety of jobs. Air gaging’s adaptability enables it to become a core function of a company’s quality control system.

Air gages accurately measure a wide variety of dimensions and are particular suited to checking dimensional relationships. Air gages are ideal for taper, parallelism, squareness, straightness, and center distance. Match gaging, which allows the selection of mating parts for a specific amount of clearance or interference, is easily done with just one reading on one dial.

As a non-contact measurement, air gaging is ideal for checking soft or highly polished material. It is also ideal for thin walled or delicate material.

Small gage heads with remote meters provide air gages with a distinct advantage in measuring multiple dimensions. Air gaging is often combined with electronic signaling to provide instant indication of part size.

Air gages can be easily adapted to measure parts in a machine. The small gage head allows an operator to make measurements while the part is still in the machine or fixture. The air also cleans the part’s measuring surface area of coolant, oil, and small chips.

Contact Thread Check Inc. to discuss your specific air gaging requirements.

http://www.threadcheck.com/content/pdf/Dim-Air-Cat-Info-Only.pdf

http://www.threadcheck.com/technical-documents/mahr-dimensionair.pdf

http://www.threadcheck.com/technical-documents/mahr-dimensonair-air-gage.pdf

http://www.threadcheck.com/technical-documents/mahr-832-dimension-air-gaging-system.pdf

http://www.threadcheck.com/technical-documents/mahr-millimar-s-1840-pe.pdf

http://www.threadcheck.com/technical-documents/mahr-dimensionair-air-gages-plugs.pdf

http://www.threadcheck.com/technical-documents/mahr-millimar-c-12081216-c-1245.pdf

 

Thread Check Inc.
900 Marconi Avenue
Ronkonkoma, NY 11779

800 767 7633
info@threadcheck.com

www.threadcheck.com

Filed under: Air Gaging No Comments
8Jan/16Off

Terms Relating to Screw Threads and Gages

Terms Relating to Screw Threads and Gages

The following terms are essential to understanding screw threads and thread gages.

http://www.threadcheck.com/terms-relating-to-screw-threads-and-gages/technicalinfo/

Thread Plug Gage- is a complete internal thread gage of either single or double-end type, comprising handle and threaded gaging member or members, with suitable locking means.

Thread Ring Gage- is an external thread gage employed for the size control of threaded work. American Gage Design – AGD style thread ring gages are adjustable with screws integrated within the gage body. Solid style ring gages are not adjustable and are more popular among international standards. Both styles of gages have their advantages and disadvantages.

Screw Thread Gages

1. Screw Thread -screw thread (hereinafter referred to as a thread), is a ridge of uniform section in the form of a helix on the external or internal surface of a cylinder, or in the form of a conical spiral on the external or internal surface of a cone or frustum of a cone. A thread formed on a cylinder is known as a “straight” or “parallel” thread, to distinguish it from a “taper” thread which is formed on a cone or frustum of a cone.

2. External and Internal Threads – An External thread is a thread on the external surface of a cylinder or cone. An internal thread is a thread on the internal surface of a hollow cylinder or cone.

3. Classes of Threads – Classes of threads are distinguished from each other by the amount of tolerance or tolerance and allowance specified. (Formerly known as “classes of fit” and so designated in Handbook H-28 [1944], government specifications, etc.)
Threaded work parts, bolts, buts, and threaded holes are usually manufactured in accordance with the thread classes standardized for industry and the Federal Services, Class 1, Class 2 and Class 3, for the American National Series and Class 1A, 1B, 2A, 2B, 3A, and 3B for the Unified Thread Series. These classes for a ½” – 13 thread plug gage are illustrated in Fig. 2. The Class chosen by any design engineer for a specific product will depend on its function in service.

Classes of Threads

4. Major Diameter- On a straight thread, the major diameter is the diameter of the imaginary co-axial cylinder which bounds the crest of an external thread or the root of an internal thread.

5. Minor Diameter- On a straight thread, the minor diameter is the diameter of an imaginary co-axial cylinder which bounds the root of an external thread or the crest of an internal thread. On a taper thread, the minor diameter, at a given position on the thread axis, is the diameter of the minor diameter cone at that position.

6. Pitch Diameter- (Simple effective diameter) On a straight thread, the pitch diameter is the diameter of an imaginary co-axial cylinder, the surface of which would pass through the thread profiles at such points as to make the width of the groove equal to one-half of the basic pitch. On a perfect thread this occurs at the point where the widths of the thread and grooves are equal. On a taper thread, the pitch diameter at a given position on the thread axis is the diameter of the pitch diameter cone at that position.

7. Pitch- The pitch of a thread is the distance, measured parallel to its axis, between corresponding points on adjacent thread forms in the axial plane and on the same side of the axis.

The pitch in inches = ________1________

Number of threads per inch

8. Lead- The lead is the distance a threaded part moves axially, with respect to a fixed mating part, in one complete rotation. On a single-thread screw the lead and pitch are identical; on a double-thread screw the lead is twice the pitch; on a triple-thread screw the lead is three times the pitch, etc.

9. Included Angle- The included angle of a thread (or angle of thread) is the angle between the flanks of the thread measured in axial plane.

10. Lead Angle- On a straight thread the lead angle is the angle made by the helix of the thread at the pitch line with a plane perpendicular to the axis. On a taper thread, the lead angle at a given axial position is the angle made by the conical spiral of the thread at the pitch line with the plane perpendicular to the axis at that position.

11. Crest- The crest is that surface of the thread which joins the flanks of thread and is farthest from the cylinder or cone from which the thread projects.

12. Root- The root is that surface of the thread which joins the flanks of adjacent thread forms and is identical with or immediately adjacent to the cylinder or cone from which the thread projects.

13. Flank or Side- The flank (or side) of a thread is either surface connecting the crest with the root, the intersection of which, with an axial plane, is a straight line.

14. Axis- The axis of a thread is the axis of its pitch cylinder or cone.

15. Base of Thread- The base of a thread is that section of the thread which coincides with the cylinder or cone from which the thread projects.

16. Depth of Thread- The distance between the crest and the base of the thread measured perpendicular to the axis.

17. Threads Per Inch- The number of threads per inch is the reciprocal of the pitch in inches.

18. Length of Thread Engagement- The length of thread engagement of two mating threads is the distance between the extreme points of contact on the pitch diameter cylinders or cones, measured parallel to the axis.

19. Depth of Thread Engagement- The depth (or height) of thread engagement between two mating threads is the distance, measured perpendicular to the axis, by which their thread forms overlap each other.

20. Pitch Line- The pitch line is the theoretical point on the thread through which would pass the imaginary cylinder or cone specified in the definition of pitch diameter.

21. Thickness of the Thread- The thickness of thread is the distance between the flanks of the thread measured at a specified position and parallel to the axis.

22. Standoff- The standoff is the axial distance between specified reference points on external and internal taper threaded members or gages, when assembled with a specified torque or under other specified conditions.

Terms Relating to Classification and Tolerances

1. Allowance- An intentional difference in the dimension of mating parts. It is the minimum clearance or the maximum interference which is intended between mating parts. It represents the condition of the tightest permissible fit, or the largest male member mated with the smallest female members.

Example:

One-half inch, Class 1, American National Coarse thread series:
Minimum pitch diameter of nut…………………………………………………………………………………………...0.4500
Maximum pitch diameter of screw……………………………………………………………………………………….0.4478
Allowance (positive)……………………………………………………………………………………………………….0.0022
One-half inch, Class 4, American National Coarse thread series:
Minimum pitch diameter of nut…………………………………………………………………………………………..0.4500
Maximum pitch diameter of screw……………………………………………………………………………………….0.4504
Allowance (negative)……………………………………………………………………………………………………...0.0004

2. Tolerance- The tolerance on a dimension is the total permissible variation in its size. The tolerance is the difference between the limits of size.

Example:

One-half inch screw, Class 1, American National Coarse thread series:
Maximum pitch diameter …………………………………………………………………………………………………0.4478
Minimum pitch diameter ………………………………………………………………………………………………….0.4404
Tolerance ………………………………………………………………………………………………………………….0.0074

3. Basic Size- The theoretical or nominal standard size from which all variations are made.

4. Crest Clearance- Defined on a screw form as the space between the crest of a thread and the root of its mating thread.

5. Finish- The character of the surface on a screw thread or other product.

6. Fit- The relation between two mating parts with reference to the conditions of assembly. The quality of fit is dependent upon both the relative size and finish of the mating parts.

7. Neutral Zone - A positive allowance. (See “Allowance.”)

8. Limits- The extreme permissible dimensions of a part.

Example:

One-half inch screw, Class 1, American National Coarse thread series:
Maximum pitch diameter 0.4478 THESE ARE
Minimum pitch diameter 0.4404 THE LIMITS

Symbols for Basic Dimensions

For use in formulas for expressing relations of screw threads, and for use on drawings and for similar purposes, the following symbols should be used:

Major diameter ………………………………………………………………………………………………D
Corresponding radius ……………………………………………………………………………………….d
Pitch Diameter ……………………………………………………………………………………………….E
Corresponding radius ……………………………………………………………………………………….e
Minor Diameter ………………………………………………………………………………………………K
Corresponding radius ……………………………………………………………………………………….k
Angle of Thread ……………………………………………………………………………………………..A
One-half angle of thread ……………………………………………………………………………………a
Number of turns per inch …………………………………………………………………………………...N
Number of threads per inch ………………………………………………………………………………...n

Lead ……………………………………………………………………………………………………..L = 1 / N

Pitch or thread interval ……………………………………………………………………………....……p = 1 / n

Helix Angle ……………………………………………………………………………………………….. s

Tangent of helix angle ……………………………………………………………………S = L / 3.14159xE

Width or basic flat at top, crest, or root …………………………………………………………………..F
Depth of basic truncation …………………………………………………………………………………..f
Depth of sharp V thread ……………………………………………………………………………………H
Depth of American National and Unified forms of thread ………………………………………………h

Length of Engagement ……………………………………………………………………………………..Q
Included angle of taper ……………………………………………………………………………………..Y
One-half included angle of taper …………………………………………………………………………..y

Symbols for Wire Measurements

Measurement over wire …………………………………………………………………………………….M
Diameter if wire ……………………………………………………………………………………………...G
Corresponding radius ……………………………………………………………………………………….g

The method of designating a screw thread by means of symbols is by the use of the initial letters of the thread series, preceded by the diameter in inches (or the screw number) and number of threads per inch, all Arabic numerals. If the thread is left-hand, the symbol “LH” shall follow the class of thread.

No symbol is used to distinguish right-hand threads. For screw threads of American National and Unified form, but of special diameters, pitches, and lengths of engagement, the symbol “NS” or “UNS” is used.

Please contact Thread Check Inc. with any questions or requirements that you may have regarding thread gages and technical specifications.

Thread Check Inc.
900 Marconi Ave.
Ronkonkoma, New York 11779

631 231 1515
info@threadcheck.com
www.threadcheck.com

13Nov/15Off

Cylindrical Plain Ring Gages

Cylindrical plain ring gages are used to check outside diameters of parts as well as for mastering measuring instruments. Plain ring gages are used to set electronic bore gages, air gages, internal micrometers and length measuring instruments. Plain ring gages are ideal for gauging the outside diameter of parts. The go ring gage is used to verify the high limit of the part and the no go plain ring gage is used to verify the low limit of the part. Cylindrical plain ring gages are offered in various materials including tool steel, chrome steel, carbide, and ceramic.

Gagemaker tolerances for cylindrical gaging products range from extremely tight class XXX to more economical class ZZ. Roundness and taper does not exceed 50% of the gagemakers tolerance. Thread Check can supply gauges from .015” up to 28.00” in diameter. The No Go ring gage is distinguished from the Go ring by an annular groove cut into the outside surface. Both ring gauges are also marked with size, type and gagemaker tolerance. The outside diameter of a plain cylindrical ring gage is knurled for easy handling and gripping. All plain cylindrical ring gauges are manufactured to ASME/ANSI B47.1 and ASME/ANSI B89.1.6. Plain ring gages up to 1.510”are manufactured without a flanged outer diameter. For ring gauges larger than 1.510”, the gages have a flanged diameter. The gage has less material on the outside of the diameter thus making it easier to handle and use by the inspector. Cylindrical plain gages manufactured in carbide use a solid carbide ring gauge jacketed with a steel outside sleeve. The jacketed steel sleeve reduces the weight and protects the carbide insert which is hard and brittle.

Thread Check’s expert sales engineers can assist you in selecting cylindrical ring gauges for your applications.

http://www.threadcheck.com/cylindrical-ring-gages-class-xx-through-zz/

Ring_Set-edit

Go/NoGo Ring Gage Set

Carbide Ring Gages

Carbide Ring Gages

Flanged Diameter Design

Flanged Diameter Design

Thread Check Inc.
900 marconi Avenue
Ronkonkoma, New York 11779

www.threadcheck.com

info@threadcheck.com

800-767-7633

 

9Oct/15Off

Alternate Size Thread Measuring Wires

It is possible to use standard 60 degree thread measuring wires to calibrate 55 degree British thread plug gages and external product. Thread Check often receives inquiries for special thread measuring wires to calibrate Whitworth/British 55 degree threads. Although Thread Check Inc. can certainly supply these special thread measuring wires, the cost is higher and the lead time to manufacture is typically 4 weeks or more. The best solution is to select a standard 60 degree thread measuring wire which is close to the 55 degree thread measuring wire diameter and simply adjust the constant value. This alternative set of thread measuring wires with an adjusted constant for the 55 degree thread angle will achieve the same exact results. The same method can be applied to 29 degree Acme and 45/7 degree buttress threads.

All “Best Size” thread measuring wires have a maximum and minimum wire diameter that may be used to measure pitch diameter. Maximum and minimum thread measuring wires should be used which are safely within the limiting dimensions given by the formulas below.

 

Include Thread Angle Max. Best Min.
60° 1.010362p .57735p .505182p
55° .82573p .563692p .50568p
29° Acme .650013p .51645p .487263p

P=pitch  n=TPI   P=1/n

The wide range of standard wire diameters in stock found within the 60 degree inch and metric sizes and the 29 degree acme sizes makes it possible to find a wire diameter very close to a required British or special size. The measurement of pitch diameter is least effected by an error in the included angle of the thread by a wire diameter which is closest to the calculated best size wire.

Related topics regarding thread measuring wires:

http://www.threadcheck.com/technical-documents/tc-thread-measuring-formulas.pdf

http://www.threadcheck.com/the-three-wire-method-of-measuring-pitch-diameter/technicalinfo/

http://www.threadcheck.com/thread-measuring-wires-the-foundation-of-proper-thread-calibration/technicalinfo/

http://www.threadcheck.com/3-wire-thread-measuring-systems-info/technicalinfo/

http://www.threadcheck.com/calibrating-thread-measuring-wires/technicalinfo/

Thread Check’s expert sales engineers can assist our customers with selecting the correct wire size and calculating the new constant value to ensure accurate measurements.

Thread Check Inc
900 Marconi Ave
Ronkonkoma, New York 11779
Tel: 800 767 7633
info@threadcheck.com
www.threadcheck.com

 

22Sep/15Off

ISO 9001: 2008 Audit Completed

We are pleased to announce that once again Thread Check Inc. passed its 2015 ISO 9001:2008 Audit with another perfect score.

ABS Quality Evaluations conducted a 1 day audit of Thread Check Inc. There were no major or minor non conformities found during the audit. This is the 6th year in row with zero nonconformities. This is a testament to our organization's continued commitment to customer satisfaction, employee empowerment and continuous improvement.

We would like to thank and congratulate all of our employees for their commitment to the quality management system.