2020 BURNDY Master Catalog

Reference

Hardware Data Recommended Tightening Torque / DURIUM™ Hexagonal Bolt Data

HARDWARE DATA

Recommended Tightening Torque The hardware used in connectors must be compatible with the connector material, have high mechanical strength and be corrosion resistant. Copper alloy connectors have hardware made of DURIUM™, which is the BURNDY trade name for silicon bronze alloy ASTMB99. This material was first introduced by BURNDY in 1927 for use in outdoor construction and today is the standard throughout the industry. Aluminum connectors generally have aluminum alloy hardware. The bolts are 2024T4 and anodized to resist corrosion. The nuts are 6061T6, which is resistant to corrosion and does not require anodizing. Bolts are lubricated to eliminate galling and to provide consistent clamping forces. The size material for clamping hardware are selected to provide the required force when tightened to the recommended torque. To reduce or greatly exceed the recommended torque can adversely affect the performance of the connector.

Steel Hardware

Recommended Torque (Inch Pounds)

Bolt Size 1/4 - 20 5/16 - 18 3/8 - 16 1/2 - 13 5/8 - 11 3/4 - 10

80

180 240 480 660

1050

Aluminum Hardware

Recommended Torque (Inch Pounds)

Bolt Size

1/2 - 13 5/8 - 11 3/4 - 10

300 480 650

DURIUM™ (Silicon Bronze) Hexagonal Bolt Data

DURIUM™ (Silicon Bronze) Hardware

Recommended Torque (in-lb)**

Min. Breaking Force (lb)

Catalog Number Series* 25X_ _ _HEB 31X_ _ _ HEB 38X_ _ _ HEB 50X_ _ _ HEB 62X_ _ _HEB 75X_ _ _HEB

Min. Shearing Force (lb)

“A” Bolt Size “B”

“C”

“D”

1/4 - 20 5/16 - 18 3/8 - 16 1/2 - 13 5/8 - 11 3/4 - 10

7/16

.50 .56 .65 .87

.16 .21 .24 .32 .40 .48

80

1,780 2,930 4,350 7,950

990

1/2

180 240 480 660

1,640 2,430 4,460 7,100

9/16

3/4

15/16 1.08 1-1/8 1.30

12,700 17,510

1050

10,540

*_ _ _ is substituted for bolt length; Consult sales representative for available lengths **These torque values develop maximum bolt preload This drawing is based on BURNDY engineering specification

www.burndy.com 1-800-346-4175 (US)

O-6