GMW GMW14657 PDF

This specification describes the test procedures and performance requirements used to evaluate the locking & sealing ability of preapplied adhesive coatings on externally threaded fasteners. Conformance to this specification is required for initial material qualification of a preapplied thread adhesive. Application specific testing requirements are also contained in this specification.

Material Description.

Three grades of material are covered by this specification:

• Grade A. Regular strength grade for use with fasteners with serviceability requirements with temperatures up to 150°C. Lower adhesive strength allows for service removal of bolts with less potential for fastener and/or mating thread damage.

• Grade B. Higher strength grade with locking/ sealing performance up to 150°C. Use of this material is not restricted to larger fastener sizes, but potential service removal concerns should be considered before use with M6 or smaller fasteners.

• Grade C. Higher strength & temperature resistant grade with locking / sealing performance up to 200°C. Use of this material is not restricted to larger fastener sizes, but potential service removal concerns should be considered before use with M6 or smaller fasteners.

Material Identification.

These materials are classified in the following grades.

• Grade A: Regular Strength: 150°C maximum

• Grade B: High Strength: 150°C maximum

• Grade C: High Strength: 200°C minimum

Typical Applications.

Externally threaded fasteners that require a preapplied adhesive for chemical locking and sealing to prevent selfloosening and loss of seal due to shock, vibration, and thermal effects.

Remarks.

The preapplied thread locking/sealing adhesive compounds are dry to the touch and remain inert on externally threaded fasteners until they are engaged into the mating internal threads. The shearing action / forces of assembly activate the adhesive. After proper cure time and temperature, the adhesive hardens to form a chemical bond between the mating threads. This bond prevents loosening of fasteners from shock, vibration, and thermal effects. These materials are also capable of providing an effective seal for water, fuel, oil, and other liquids used in the assembly of automotive and related products.

These materials are not reusable after activation of the curing process during assembly.