Lakshmi Precision Screws Limited

Alloy hexagon socket head sholder screw inches / ANSI - B 18.3

DIMENSIONS :	ANSI - B 18.3 (EQUIVALENT TO BS 2470)
THREAD :	3 A CLASS
HARDNESS :	38 -43HRS
TENSILE STRENGHT :	140 KSI BASED ON MIN STRESS AREA AT THD. NECKPORTION.
MATERIAL :	HIGH GRADE ALLOY STEEL
DESIGNATION :	EXAMPLE : • SHOULDERSCREW 5/16 x 1-1/4 (1/4-20 UNC) • SHOULDER DIA 5/16" • SHOULDER LENGHT 1-1/4 • THREAD SIZE 1/4 - 20UNC
ALSO AVAILBLE IN STAINLESS STEEL

Nominal Size

Ø 1/8

Ø 3/16

Ø 1/4

Ø 5/16

Ø 3/8

Ø 1/2

Ø 5/8

Ø 3/4

Ø 1

ds	Max.
	Min.

0.1244

0.1868

0.2480

0.3105

0.3730

0.4980

0.6230

0.7480

0.9980

0.1236

0.1858

0.2460

0.3085

0.3710

0.4960

0.6210

0.7460

0.9960

d (THD. Size)

#4-40

#8-32

#10.24

1/4"-20

5/16"-18

3/8"-16

1/2"-13

5/8"-11

3/4"-10

0.157

0.189

0.375

0.438

0.500

0.625

0.750

0.825

1.000

0.250

0.311

0.375

0.438

0.562

0.750

0.875

1.000

1.312

0.125

0.157

0.188

0.219

0.250

0.312

0.375

0.500

0.625

S (Key Size)

5/64

3/32

1/8

5/32

3/16

1/4

5/16

3/8

1/2

t (Min.)

0.067

0.079

0.094

0.117

0.141

0.188

0.234

0.281

0.375