The TAPTITE® family of fasteners performs well in large diameter sizes in deep thread engagements. In the past, the limitations of case hardened products restricted the exploitation of in-place cost savings for larger diameter TRILOBULAR fasteners. However, TAPTITE® screws and bolts are available with three different types of heat treatment: CORFLEX®-'I', CORFLEX®-'N', and case hardened, making the fasteners adaptable to a wider variety of applications.
CORFLEX®-'I' TAPTITE® bolts are neutral hardened to grade strength, metric 8.8, 9.8, 10.9 or any intermediate value. The thread forming zone is selectively induction hardened in order to form threads in untapped nuts. CORFLEX®-'I' heat treatment allows TAPTITE® thread rolling bolts to provide in-place cost savings in large structural applications with strength, ductility and toughness equal to grade strength machine screws or bolts. CORFLEX®-'I' heat treatment to Grade 10.9 level is standard for TAPTITE® bolts in sizes 6mm (1/4") and larger.
CORFLEX®-'N' fasteners are neutral hardened to grade 10.9 strength level. CORFLEX®-'N' products are designed to be used in "soft white" metals such as aluminum or zinc alloys. CORFLEX®-'N' heat treatment can be specified for any size TAPTITE® screws or bolts that are intended to be used in aluminum or zinc alloys.
Case hardening is the standard heat treatment for all TAPTITE® screws in sizes 5mm (#10) and smaller.
Pin-point precision of high hardness zone in axial section of a CORFLEX®-'I' fastener is shown by the crescent shaped areas in chemically etched mount.