KATO STI Gages

KATO STI Gages

Precision that ensures Accuracy.

KATO CoilThread STI (Screw Thread Insert) Thread Plug Gages are designed to check the accuracy of the internal thread of an STI tapped hole. Gaging the tapped hole prior to installation of the insert is critical to ensure the accuracy of the finished thread. If the tapped hole gauges correctly, the finished thread will also be accurate once the insert is properly installed and seated.

It is not necessary to gage the installed insert. Gaging of the tapped thread is specified because a standard gage may not freely enter an installed insert. The insert will seat itself once a bolt or screw is installed and tightened (Ref. NASM33537). In fact, it is not possible to gage a locking type insert because of the locking coil.

KATO offers two types of STI Thread Plug Gages (for unified sizes):


Working Gages

Recommended for production use since their greater tolerance allows for more wear.

Reference Gages

Pitch diameters at or very close to the basic size and are to be used as master gages.

KATO CoilThread Gages include a "GO" and "HI" (NO GO) member. The Working Gage "GO" member has a 0.0002 wear allowance on the pitch diameter. The "GO" member checks the basic pitch diameter, major diameter minimum and lead. The "HI" member checks the maximum pitch diameter. The minor diameter must be checked separately with a graduated pin set.


Features & Benefits

  • Available in 3B or 2B (Unified); 4H or 5H (Metric) Class of Fit.
  • Available for a full range of Unified and Metric thread sizes.
  • Ensures accuracy of the finished threads.
  • Compatiable with screw thread inserts from Heli-Coil, Recoil and others.
  • Lower cost than similar gages from competitors.

Part Numbers


For fast and accurate part numbers and technical information on specific inserts try out the KATO Product Wizard.

Example of a KATO CoilThread Gage part number:


CG C - 02 X - 3B

 1   2    3  4     5


1
Tool Type
2
Thread Designation
3
Size Designation
4
Style / Type
5
Class of Fit
CG - CoilThread Gage (STI) C- Unified Coarse
F - Unified Fine
M - Metric
Chart Below X - Working
W - References
See Notes at the bottom
Thread
Size
Working Gages Reference Gages
3B 2B 3B 2B
Unified Coarse
2-56CGC-02X-3BCGC-02X-2BCGC-02W-3BCGC-02W-2B
3-48CGC-03X-3BCGC-03X-2BCGC-03W-3BCGC-03W-2B
4-40CGC-04X-3BCGC-04X-2BCGC-04W-3BCGC-04W-2B
5-40CGC-05X-3BCGC-05X-2BCGC-05W-3BCGC-05W-2B
6-32CGC-06X-3BCGC-06X-2BCGC-06W-3BCGC-06W-2B
8-32CGC-2X-3BCGC-2X-2BCGC-2W-3BCGC-2W-2B
10-24CGC-3X-3BCGC-3X-2BCGC-3W-3BCGC-3W-2B
12-24CGC-1X-3BCGC-1X-2BCGC-1W-3BCGC-1W-2B
1/4-20CGC-4X-3BCGC-4X-2BCGC-4W-3BCGC-4W-2B
5/16-18CGC-5X-3BCGC-5X-2BCGC-5W-3BCGC-5W-2B
3/8-16CGC-6X-3BCGC-6X-2BCGC-6W-3BCGC-6W-2B
7/16-14CGC-7X-3BCGC-7X-2BCGC-7W-3BCGC-7W-2B
1/2-13CGC-8X-3BCGC-8X-2BCGC-8W-3BCGC-8W-2B
9/16-12CGC-9X-3BCGC-9X-2BCGC-9W-3BCGC-9W-2B
5/8-11CGC-10X-3BCGC-10X-2BCGC-10W-3BCGC-10W-2B
3/4-10CGC-12X-3BCGC-12X-2BCGC-12W-3BCGC-12W-2B
7/8-9CGC-14X-3BCGC-14X-2BCGC-14W-3BCGC-14W-2B
1-8CGC-16X-3BCGC-16X-2BCGC-16W-3BCGC-16W-2B
1-1/8-7CGC-18X-3BCGC-18X-2BCGC-18W-3BCGC-18W-2B
1-1/4-7CGC-20X-3BCGC-20X-2BCGC-20W-3BCGC-20W-2B
1-3/8-6CGC-22X-3BCGC-22X-2BCGC-22W-3BCGC-22W-2B
1-1/2-6CGC-24X-3BCGC-24X-2BCGC-24W-3BCGC-24W-2B
Unified Fine
0-80CGF-00X-3BCGF-00X-2BCGF-00W-3BCGF-00W-2B
3-56CGF-03X-3BCGF-03X-2BCGF-03W-3BCGF-03W-2B
4-48CGF-04X-3BCGF-04X-2BCGF-04W-3BCGF-04W-2B
6-40CGF-06X-3BCGF-06X-2BCGF-06W-3BCGF-06W-2B
8-36CGF-2X-3BCGF-2X-2BCGF-2W-3BCGF-2W-2B
10-32CGF-3X-3BCGF-3X-2BCGF-3W-3BCGF-3W-2B
1/4-28CGF-4X-3BCGF-4X-2BCGF-4W-3BCGF-4W-2B
5/16-24CGF-5X-3BCGF-5X-2BCGF-5W-3BCGF-5W-2B
3/8-24CGF-6X-3BCGF-6X-2BCGF-6W-3BCGF-6W-2B
7/16-20CGF-7X-3BCGF-7X-2BCGF-7W-3BCGF-7W-2B
1/2-20CGF-8X-3BCGF-8X-2BCGF-8W-3BCGF-8W-2B
9/16-18CGF-9X-3BCGF-9X-2BCGF-9W-3BCGF-9W-2B
5/8-18CGF-10X-3BCGF-10X-2BCGF-10W-3BCGF-10W-2B
3/4-16CGF-12X-3BCGF-12X-2BCGF-12W-3BCGF-12W-2B
7/8-14CGF-14X-3BCGF-14X-2BCGF-14W-3BCGF-14W-2B
1-12CGF-161X-3BCGF-161X-2B CGF-161W-3BCGF-161W-2B
1-14CGF-16X-3BCGF-16X-2B CGF-16W-3BCGF-16W-2B
1-1/8-12CGF-18X-3BCGF-18X-2B CGF-18W-3BCGF-18W-2B
1-1/4-12CGF-20X-3BCGF-20X-2B CGF-20W-3BCGF-20W-2B
1-3/8-12CGF-22X-3BCGF-22X-2B CGF-22W-3BCGF-22W-2B
1-1/2-12CGF-24X-3BCGF-24X-2B CGF-24W-3BCGF-24W-2B
Thread
Size
Working Gages
3B 2B
Metric Coarse
M2X0.4CGM-2X.4-4HCGM-2X.4-5H
M2.2X.45CGM-2.2X.45-4HCGM-2.2X.45-5H
M2.5X.45CGM-2.5X.45-4HCGM-2.5X.45-5H
M3X.5CGM-3X.5-4HCGM-3X.5-5H
M3.5X.6CGM-3.5X.6-4HCGM-3.5X.6-5H
M4X.7CGM-4X.7-4HCGM-4X.7-5H
M5X.8CGM-5X.8-4HCGM-5X.8-5H
M6X1CGM-6X1-4HCGM-6X1-5H
M7X1CGM-7X1-4HCGM-7X1-5H
M8X1.25CGM-8X1.25-4HCGM-8X1.25-5H
M10X1.5CGM-10X1.5-4HCGM-10X1.5-5H
M12X1.75CGM-12X1.75-4HCGM-12X1.75-5H
M14X2CGM-14X2-4HCGM-14X2-5H
M16X2CGM-16X2-4HCGM-16X2-5H
M18X2.5CGM-18X2.5-4HCGM-18X2.5-5H
M20X2.5CGM-20X2.5-4HCGM-20X2.5-5H
M22X2.5CGM-22X2.5-4HCGM-22X2.5-5H
M24X3CGM-24X3-4HCGM-24X3-5H
M27X3CGM-27X3-4HCGM-27X3-5H
Metric Fine
M8X1CGM-8X1-4HCGM-8X1-5H
M10X1CGM-10X1-4HCGM-10X1-5H
M10X1.25CGM-10X1.25-4HCGM-10X1.25-5H
M12X1.25CGM-12X1.25-4HCGM-12X1.25-5H
M12X1.5CGM-12X1.5-4HCGM-12X1.5-5H
M14X1.5CGM-14X1.5-4HCGM-14X1.5-5H
M16X1.5CGM-16X1.5-4HCGM-16X1.5-5H
M18X1.5CGM-18X1.5-4HCGM-18X1.5-5H
M20X1.5CGM-20X1.5-4HCGM-20X1.5-5H
M22X1.5CGM-22X1.5-4HCGM-22X1.5-5H
M18X2CGM-18X2-4HCGM-18X2-5H
M20X2CGM-20X2-4HCGM-20X2-5H
M22X2CGM-22X2-4HCGM-22X2-5H
M24X2CGM-24X2-4HCGM-24X2-5H
M27X2CGM-27X2-4HCGM-27X2-5H
M30X2CGM-30X2-4HCGM-30X2-5H
M39X2CGM-39X2-4HCGM-39X2-5H
M36X3CGM-36X3-4HCGM-36X3-5H
M39X3CGM-39X3-4HCGM-39X3-5H

Please Note:

  • The Working Gage "GO" member has a .0002 wear allowance on the pitch diameter.
  • Gaging of the tapped thread is specified because a standard gage may not freely enter an installed insert. The insert will seat itself once a bolt or screw is installed and tightened.
  • The "GO" member checks basic pitch diameters, major diameter minimum and lead. The "HI" member checks maximum pitch diameter. Minior diameter is checked separately with a graduated pin set, for example.
  • The Class of Fit specifies the pitch diameter tolerance of the tapped hole, with class 3B (Unified) and 4H (Metric) being the tighter range usually specified in military/aerospace applications. Class 2B (Unified) and 5H (Metric) gages have a broader tolerance range and are normally specified in commerical/industrial applications.

Specifications

All dimensions for unified sizes in inches | All dimensions for metric sizes in millimeter | All dimensions are are for reference only.

gages

Thread
Size
Pitch Diameter (in) Length
A
3B 2B
Go NoGo Go NoGo
Unified Coarse
2-560.09760.09890.09760.09962.5
3-480.11260.1140.11260.11482.5
4-400.12830.12990.12830.13082.9
5-400.14130.1430.14130.14382.9
6-320.15830.16010.15830.16112.9
8-320.18430.18620.18430.18723.1
10-240.2170.21920.2170.22033.1
12-240.2430.24530.2430.24643.1
1/4-200.28250.28510.28250.28633.5
5/16-180.34860.35150.34860.35293.5
3/8-160.41560.41890.41560.42034.6
7/16-140.48390.48750.48390.4894.6
1/2-130.54990.55370.54990.55544.6
9/16-120.61670.62080.61670.62255.1
5/8-110.68410.68850.68410.69035.1
3/4-100.81490.81960.81490.82165.1
7/8-90.94710.95220.94710.95435.8
1-81.08121.08681.08121.08685.8
1-1/8-71.21781.22391.21781.22625.8
1-1/4-71.34281.3491.34281.35146.8
1-3/8-61.48321.491.48321.49266.8
1-1/2-61.60821.61511.60821.61776.8
Unified Fine
0-800.06810.06900.06810.06972.9
3-560.11060.11190.11060.11262.5
4-480.12560.12710.12560.12792.9
6-400.15430.15600.15430.15692.9
8-360.18210.18400.18210.18493.1
10-320.21030.21230.21030.21333.1
1/4-280.27320.27540.27320.27654.0
5/16-240.33950.34210.33950.34334.0
3/8-240.40200.40470.40200.40594.6
7/16-200.47000.47310.47000.47444.6
1/2-200.53250.53570.53250.53714.6
9/16-180.59860.60200.59860.60355.1
5/8-180.66110.66460.66110.66615.1
3/4-160.79060.79450.79060.79615.1
7/8-140.92140.92570.92140.92745.8
1-121.05421.05891.05421.06085.8
1-1/8-121.17921.18411.17921.18605.8
1-1/4-121.30421.30921.30421.31126.8
1-3/8-121.42921.43431.42921.43646.8
1-1/2-121.55421.55951.55421.56156.8
Thread
Size
Pitch Diameter (mm) Length
A
4H 5H
Go NoGo Go NoGo
Metric Coarse
M2X0.42.2602.2952.2602.31063.5
M2.2X0.452.4922.5322.4922.54763.5
M2.5X0.452.7922.8322.7922.84763.5
M3X0.53.3253.3673.3253.38473.6
M3.5X0.63.8903.9403.8903.95973.6
M4X0.74.4554.5094.4554.52978.7
M5X0.85.5205.5775.5205.59778.7
M6X16.6506.7196.6506.742101.6
M7X17.6507.7197.6507.742101.6
M8X1.258.8128.8868.8128.911101.6
M10X1.510.97411.06110.97411.089116.8
M12X1.7513.13713.23613.13713.271116.8
M14X215.29915.40615.29915.444129.5
M16X217.29917.40617.29917.444129.5
M18X2.519.62419.73819.62419.778129.5
M20X2.521.62421.73821.62421.778129.5
M22X2.523.62423.73823.62423.778129.5
M24X325.94826.09325.94826.135147.3
M27X328.94829.09328.94829.135147.3
Metric Fine
M8X18.6508.7198.6508.742101.6
M10X110.65010.71910.65010.742116.8
M10X1.2510.81210.88610.81210.911116.8
M12X1.2512.81212.89812.81212.926116.8
M12X1.512.97413.06712.97413.099116.8
M14X1.514.97415.06714.97415.099129.5
M16X1.516.97417.06716.97417.099129.5
M18X1.518.97419.06718.97419.099129.5
M20X1.520.97421.06720.97421.099129.5
M22.1522.97423.06722.97423.099129.5
M18X219.29919.40619.29919.444129.5
M20X221.29921.40621.29921.444129.5
M22X223.29923.40623.29923.444129.5
M24X225.29925.41425.29925.454147.3
M27X228.29928.41428.29928.455147.3
M30X231.29931.41431.29931.454147.3
M39X240.29940.41440.29940.454171.5
M36X337.94838.09337.94838.135171.5
M39X340.94841.09340.94841.135171.5

Cross Reference


KATO
Part Number
Heli-Coil
Part Number
KATO Part
Number
Heli-Coil
Part Number
KATO Part
Number
Heli-Coil
Part Number
KATO
Part Number
Heli-Coil
Part Number
3B Working 2B Working 3B Reference 2B Reference
Unified Coarse
CGC-02X-3B3688-02CGC-02X-2B1442-02CGC-02W-3B1688-02CGC-02W-2B1440-02
CGC-03X-3B3688-03CGC-03X-2B1442-03CGC-03W-3B1688-03CGC-03W-2B1440-03
CGC-04X-3B3688-04CGC-04X-2B1442-04CGC-04W-3B1688-04CGC-04W-2B1440-04
CGC-05X-3B3688-05CGC-05X-2B1442-05CGC-05W-3B1688-05CGC-05W-2B1440-05
CGC-06X-3B3688-06CGC-06X-2B1442-06CGC-06W-3B1688-06CGC-06W-2B1440-06
CGC-2X-3B3688-2CGC-2X-2B1442-2CGC-2W-3B1688-2CGC-2W-2B1440-2
CGC-3X-3B3688-3CGC-3X-2B1442-3CGC-3W-3B1688-3CGC-3W-2B1440-3
CGC-1X-3B3688-1CGC-1X-2B1442-1CGC-1W-3B1688-1CGC-1W-2B1440-1
CGC-4X-3B3688-4CGC-4X-2B1442-4CGC-4W-3B1688-4CGC-4W-2B1440-4
CGC-5X-3B3688-5CGC-5X-2B1442-5CGC-5W-3B1688-5CGC-5W-2B1440-5
CGC-6X-3B3688-6CGC-6X-2B1442-6CGC-6W-3B1688-6CGC-6W-2B1440-6
CGC-7X-3B3688-7CGC-7X-2B1442-7CGC-7W-3B1688-7CGC-7W-2B1440-7
CGC-8X-3B3688-8CGC-8X-2B1442-8CGC-8W-3B1688-8CGC-8W-2B1440-8
CGC-9X-3B3688-9CGC-9X-2B1442-9CGC-9W-3B1688-9CGC-9W-2B1440-9
CGC-10X-3B3688-10CGC-10X-2B1442-10CGC-10W-3B1688-10CGC-10W-2B1440-10
CGC-12X-3B3688-12CGC-12X-2B1442-12CGC-12W-3B1688-12CGC-12W-2B1440-12
CGC-14X-3B3688-14CGC-14X-2B1442-14CGC-14W-3B1688-14CGC-14W-2B1440-14
CGC-16X-3B3688-16CGC-16X-2B1442-16CGC-16W-3B1688-16CGC-16W-2B1440-16
CGC-18X-3B3688-18CGC-18X-2B1442-18CGC-18W-3B1688-18CGC-18W-2B1440-18
CGC-20X-3B3688-20CGC-20X-2B1442-20CGC-20W-3B1688-20CGC-20W-2B1440-20
CGC-22X-3B3688-22CGC-22X-2B1442-22CGC-22W-3B1688-22CGC-22W-2B1440-22
CGC-24X-3B3688-24CGC-24X-2B1442-24CGC-24W-3B1688-24CGC-24W-2B1440-24
Unified Fine
CGF-03X-3B3694-03CGF-03X-2B1443-03CGF-03W-3B1694-03CGF-03W-2B1441-03
CGF-04X-3B3694-04CGF-04X-2B1443-04CGF-04W-3B1694-04CGF-04W-2B1441-04
CGF-06X-3B3694-06CGF-06X-2B1443-06CGF-06W-3B1694-06CGF-06W-2B1441-06
CGF-2X-3B3694-2CGF-2X-2B1443-2CGF-2W-3B1694-2CGF-2W-2B1441-2
CGF-3X-3B3694-3CGF-3X-2B1443-3CGF-3W-3B1694-3CGF-3W-2B1441-3
CGF-4X-3B3694-4CGF-4X-2B1443-4CGF-4W-3B1694-4CGF-4W-2B1441-4
CGF-5X-3B3694-5CGF-5X-2B1443-5CGF-5W-3B1694-5CGF-5W-2B1441-5
CGF-6X-3B3694-6CGF-6X-2B1443-6CGF-6W-3B1694-6CGF-6W-2B1441-6
CGF-7X-3B3694-7CGF-7X-2B1443-7CGF-7W-3B1694-7CGF-7W-2B1441-7
CGF-8X-3B3694-8CGF-8X-2B1443-8CGF-8W-3B1694-8CGF-8W-2B1441-8
CGF-9X-3B3694-9CGF-9X-2B1443-9CGF-9W-3B1694-9CGF-9W-2B1441-9
CGF-10X-3B3694-10CGF-10X-2B1443-10CGF-10W-3B1694-10CGF-10W-2B1441-10
CGF-12X-3B3694-12CGF-12X-2B1443-12CGF-12W-3B1694-12CGF-12W-2B1441-12
CGF-14X-3B3694-14CGF-14X-2B1443-14CGF-14W-3B1694-14CGF-14W-2B1441-14
CGF-16X-3B3694-16CGF-16X-2B1443-16CGF-16W-3B1694-16CGF-16W-2B1441-16
CGF-18X-3B3694-18CGF-18X-2B1443-18CGF-18W-3B1694-18CGF-18W-2B1441-18
CGF-20X-3B3694-20CGF-20X-2B1443-20CGF-20W-3B1694-20CGF-20W-2B1441-20
CGF-22X-3B3694-22CGF-22X-2B1443-22CGF-22W-3B1694-22CGF-22W-2B1441-22
CGF-24X-3B3694-24CGF-24X-2B1443-24CGF-24W-3B1694-24CGF-24W-2B1441-24
KATO
Part Number
Heli-Coil
Part Number
KATO
Part Number
Heli-Coil
Part Number
4H Working 5H Working
Metric Coarse
CGM-2X.4-4H4624-2CGM-2X.4-5H1324-2
CGM-2.2X.45-4H4624-2.2CGM-2.2X.45-5H1324-2.2
CGM-2.5X.45-4H4624-2.5CGM-2.5X.45-5H1324-2.5
CGM-3X.5-4H4624-3CGM-3X.5-5H1324-3
CGM-3.5X.6-4H4624-3.5CGM-3.5X.6-5H1324-3.5
CGM-4X.7-4H4624-4CGM-4X.7-5H1324-4
CGM-5X.8-4H4624-5CGM-5X.8-5H1324-5
CGM-6X1-4H4624-6CGM-6X1-5H1324-6
CGM-7X1-4H4624-7CGM-7X1-5H1324-7
CGM-8X1.25-4H4624-8CGM-8X1.25-5H1324-8
CGM-10X1.5-4H4624-10CGM-10X1.5-5H1324-10
CGM-12X1.75-4H4624-12CGM-12X1.75-5H1324-12
CGM-14X2-4H4624-14CGM-14X2-5H1324-14
CGM-16X2-4H4624-16CGM-16X2-5H1324-16
CGM-18X2.5-4H4624-18CGM-18X2.5-5H1324-18
CGM-20X2.5-4H4624-20CGM-20X2.5-5H1324-20
CGM-22X2.5-4H4624-22CGM-22X2.5-5H1324-22
CGM-24X3-4H4624-24CGM-24X3-5H1324-24
Metric Fine
CGM-8X1-4H5416-8CGM-8X1-5H4916-8
CGM-10X1-4H5416-10CGM-10X1-5H4916-10
CGM-10X1.25-4H5424-10CGM-10X1.25-5H4924-10
CGM-12X1.25-4H5424-12CGM-12X1.25-5H4924-12
CGM-12X1.5-4H5480-12CGM-12X1.5-5H4980-12
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