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Grade Markings Help You Choose the Right
Fastener for Your Project
Head markings on cap screws are your
assurance that the fastener you choose will do
the job it's designed to do.
The Society of Automotive Engineers and the
Industrial Fasteners Institute have established
specific ranges of hardness and tensile strength
for each grade of fastener. All Elco fasteners
meet or exceed these requirements.
There are certain applications which
engineers have determined are appropriate for
the various grade of fasteners.
Do-it-yourselfers can use the grade markings to
be sure the bolt or cap screw will meet their
requirements.
Grade 2 Fasteners
Often referred to as "hardware" quality,
these fasteners are typically made of low-carbon
steel. They are ideally suited for holding wood
pieces together (in combination with appropriate
nuts and washers) or general hardware use where
higher strength is not required.
There is no grade marking on the head of
Grade 2 fasteners, although many manufacturers
will put a distinguishing company identification
on the head. |
Grade 5 Fasteners
Grade 5 fasteners are made of medium-carbon
steel. These fasteners are then quenched and
tempered for the additional strength necessary
for most automotive uses and other applications
where strength is a moderate concern.
The grade marking on the head of a Grade 5
fastener is three equally-spaced lines coming
out from the center of the head. Manufacturers`
identifications are added for traceability.
Grade 8 Fasteners
Grade 8 fasteners are manufactured of
medium-carbon alloy steel for the most demanding
applications. These fasteners are then quenched
and tempered to superior strength and hardness
qualities.
The grade marking on a Grade 8 fastener is six
equally spaced lines coming out from the center
of the head. Once again, the manufacturer's mark
is necessary for traceability.
Do not confuse the use of Grade 8.2 boron
bolts with true Grade 8 fasteners. The two
grades have different characteristics and should
not be used interchangeably. |
