2026 PRICE BOOK - REV K - 04.27.2026

HELICAL COIL (STI) THREAD PLUG GAGES STEEL

GSG

GSG

Helical Coil (STI) Plug Gages are used to gage threaded holes prior to insertion of screw thread inserts. Screw thread inserts are used to repair a damaged thread or to provide a stronger threaded assembly. All Helical Coil Plug Gages are manufactured of hardened tool steel to class X tolerance. For class W contact factory. All stocked gages are marked in fraction and decimal.

Inch

Nominal

Go

NoGo

Go

NoGo 2B NoGo 3B Member

Handle

Handle Double End

Size

Length

Length

Pitch

Pitch

Pitch

List

#

Price Go/NoGo/Hdle

"L"

"L"

Diameter

Diameter

Diameter

Price

List Price

2-56 (.086) UNC

5/16

7/32

0.0976

0.0996

0.0989

$

84.00

00

$

16.00

$

184.00

3-48 (.099) UNC

5/16

7/32

0.1126

0.1148

0.1140

$

80.00

00

$

16.00

$

176.00

3-56 (.099) UNF

5/16

7/32

0.1106

0.1126

0.1119

$

80.00

00

$

16.00

$

176.00

4-40 (.112) UNC

5/16

7/32

0.1283

0.1308

0.1299

$

75.00

00

$

16.00

$

166.00

4-48 (.112) UNF

5/16

7/32

0.1256

0.1279

0.1271

$

75.00

00

$

16.00

$

166.00

5-40 (.125) UNC

13/32

9/32

0.1413

0.1438

0.1430

$

75.00

0

$

16.00

$

166.00

6-32 (.138) UNC

13/32

9/32

0.1583

0.1611

0.1601

$

75.00

0

$

16.00

$

166.00

6-40 (.138) UNF

13/32

9/32

0.1543

0.1569

0.1560

$

75.00

0

$

16.00

$

166.00

8-32 (.164) UNC

13/32

9/32

0.1843

0.1872

0.1862

$

72.00

0

$

16.00

$

160.00

8-36 (.164) UNF

13/32

9/32

0.1821

0.1849

0.1840

$

72.00

0

$

16.00

$

160.00

10-24 (.190) UNC

1/2

5/16

0.2170

0.2203

0.2192

$

72.00

0

$

16.00

$

160.00

10-32 (.190) UNF

1/2

5/16

0.2103

0.2133

0.2123

$

72.00

0

$

16.00

$

160.00

12-24 (.216) UNC

1/2

5/16

0.2430

0.2464

0.2453

$

72.00

1

$

16.00

$

160.00

1/4-20 UNC

1/2

5/16

0.2825

0.2864

0.2851

$

69.00

1

$

16.00

$

154.00

1/4-28 UNF

1/2

5/16

0.2732

0.2765

0.2754

$

69.00

1

$

16.00

$

154.00

5/16-18 UNC

3/4

3/8

0.3486

0.3529

0.3515

$

69.00

2

$

18.00

$

156.00

5/16-24 UNF

3/4

3/8

0.3395

0.3433

0.3421

$

69.00

2

$

18.00

$

156.00

3/8-16 UNC

3/4

3/8

0.4156

0.4203

0.4189

$

72.00

2

$

18.00

$

162.00

3/8-24 UNF

3/4

3/8

0.4020

0.4059

0.4047

$

72.00

2

$

18.00

$

162.00

7/16-14 UNC

7/8

1/2

0.4839

0.4890

0.4875

$

75.00

3

$

18.00

$

168.00

7/16-20 UNF

7/8

1/2

0.4700

0.4744

0.4731

$

75.00

3

$

18.00

$

168.00

1/2-13 UNC

7/8

1/2

0.5499

0.5554

0.5537

$

80.00

3

$

18.00

$

178.00

1/2-20 UNF

7/8

1/2

0.5325

0.5371

0.5357

$

80.00

3

$

18.00

$

178.00

9/16-12 UNC

7/8

1/2

0.6167

0.6225

0.6208

$

96.00

3

$

18.00

$

210.00

9/16-18 UNF

7/8

1/2

0.5986

0.6035

0.6020

$

96.00

3

$

18.00

$

210.00

5/8-11 UNC

7/8

1/2

0.6841

0.6903

0.6885

$

96.00

3

$

18.00

$

210.00

5/8-18 UNF

7/8

1/2

0.6611

0.6661

0.6646

$

96.00

3

$

18.00

$

210.00

3/4-10 UNC

1

5/8

0.8149

0.8216

0.8196

$

100.00

4

$

18.00

$

218.00

3/4-16 UNF

1

5/8

0.7906

0.7961

0.7945

$

100.00

3

$

18.00

$

218.00

19

Effective April 2026 - © Glastonbury Southern Gage