Bolt - Square, ANSI (in)

Written by Matt Milbury. Posted in Bolt Datasheets

ASME Standards

  • ASME B18.2.1

Length (L) of a square bolt is measured from underside of head to the end of the bolt.

Nut

Nut

Bolt

Size

Body Diameter

D

Width Across Flat

A

Width Across Corner

B

Thickness

C

Max

Min

Basic

Max

Min

Max

Min

Basic

Max

Min

1/4

0.260

0.237

7/16

0.375

0.362

0.530

0.498

7/32

0.188

0.156

5/16

0.324

0.298

1/2

0.500

0.484

0.707

0.665

17/64

0.220

0.186

3/8

0.388

0.360

5/8

0.562

0.544

0.795

0.747

21/64

0.268

0.232

7/16

0.452

0.421

3/4

0.625

0.603

0.884

0.828

9/32

0.316

0.278

1/2

0.515

0.482

13/16

0.750

0.725

1.061

0.995

7/16

0.348

0.308

5/8

0.642

0.605

1

0.938

0.906

1.326

1.244

35/64

0.444

0.400

3/4

0.768

0.729

1 1/8

1.125

1.088

1.591

1.494

21/32

0.524

0.476

7/8

0.895

0.852

1 5/16

1.312

1.269

1.856

1.742

49/64

0.620

0.568

1

1.022

0.976

1 1/2

1.500

1.450

2.121

1.991

7/8

0.684

0.628

1 1/8

1.149

1.098

1 11/16

1.688

1.631

2.386

2.239

1

0.780

0.720

1 1/4

1.277

1.223

1 7/8

1.875

1.812

2.652

2.489

1 3/32

0.876

0.812

1 3/8

1.404

1.345

2 1/16

2.062

1.994

2.917

2.738

1 13/64

0.940

0.872

1 1/2

1.531

1.470

2 1/4

2.250

2.175

3.182

2.986

1 5/16

1.036

0.964