© 2014 Simpson Strong-T
ie Company Inc.
-12-
PRINCIPLES AND GUIDELINES FOR PROPER FASTENING
FISH-HOOKING
“Fish-hooking” is when the fastener curves when driven into concrete. This is
caused by the fastener hitting large, hard, or excessive amounts of aggregate,
rebar, or any hard object. Fish-hooking can reduce the holding power of the
fastener, result in spalling, and may increase unsafe conditions due to
escaping particles. Fish-hooking can be minimized by:
- Reducing shank penetration
- Increasing shank diameter
- Using appropriate powder load level. Excessive powder can
cause over-driving.
- Fastening through a metal disc
FASTENING INTO STEEL
The most common type of steel fastened into is structural steel in the form
of beam, angle iron, channel, tee, plate, and strip. The holding power of the
powder-actuated fastener is a function of the gripping action of the steel
base material around the fastener, and the fusion of the fastener to the
base material.
FACTORS THAT INFLUENCE THE HOLDING POWER
OF FASTENERS IN STEEL
- Shank diameter: Larger shank diameters increase holding power
- Thickness of steel base material: Thicker base material increases
holding power
- Fastener point penetration: Getting the point to pass through base
material by approximately
1
⁄
4
" maximizes holding power
- Knurled fasteners: Knurling on the fastener provides interlocking of
the shank and the base material, which increases the holding power
GENERAL RULES:
Minimum spacing of fasteners into steel is 1
1
⁄
2
". Minimum edge distance of
fasteners into steel is
1
⁄
2
". Steel thickness must be no less than the shank
diameter of the fastener.
Summary of Contents for PT-22A
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