© 2013 Simpson Strong-T
ie Company Inc.
© 2013 Simpson Strong-T
ie Company Inc.
-11-
-12-
PRINCIPLES AND GUIDELINES FOR PROPER FASTENING
FASTENING INTO MASONRY MATERIALS:
Masonry materials suitable for fastening into include:
- Poured concrete
- Precast concrete
- Pre-stressed concrete
- Grout illed concrete block
- Grouted joints
Fasteners are primarily held into masonry by a clamping of the
concrete around the fastener. Factors that inluence a fastener driven
into concrete include:
- Depth of penetration
- Compressive strength of concrete
- Fastener spacing and edge distance
- Fastener shank diameter
- Concrete aggregate
.145" Dia.
Shank Penetration
\
" Stud
Penetration
Concrete Block & Joints
1"-1
¼
"
1
½
"-1
¾
"
Concrete 2000-2500 psi
9-10 times Shank Dia.
or 1
¼
" -1
½
"
1"-1
½
"
Concrete 2500-4000 psi
7-8 times shank Dia.
or 1"-1
¼
"
1"-1
½
"
Precast or prestressed
concrete 4,000 psi
5-6 times shank Dia.
or
⅞
"-1
¼
"
⅞
"-1"
PROPER DEPTH OF PENETRATION:
FASTENER EDGE DISTANCE ON CONCRETE:
Distance should be no closer than 3".
MINIMUM DISTANCE BETWEEN FASTENINGS:
.300 and 8 mm headed fasteners – 3" spacing.
\
" and
\
" threaded fasteners – 6" spacing.
CONCRETE THICKNESS:
Concrete thickness must be at least 3 times the fastener penetration.
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 power 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 ARE:
- 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
¼
" 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
½
". Minimum edge distance of
fasteners into steel is
½
". Steel Thickness must be no less than the shank
diameter of the fastener.