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PEM® self-clinching studs are installed by placing them in properly sized holes in the sheets and squeezing into place with any standard press. The squeezing action embeds the head of the stud into the sheet. The metal displaced by the head flows smoothly and evenly around the ribs and into the annular groove - creating a flushhead assembly and securely locking the stud into the sheet with high torque-out and pushout resistances.

HFH (heavy-duty) Studs replace weld studs with easier installation at lower costs. The large stud head which projects above the sheet material distributes the axial tightening force over a large area thereby improving pull through resistance.

HFG8 and HF109 (heavy-duty high tensile strength) Studs are manufactured for the most demanding applications from medium carbon alloy steel, then heat-treated to high strength and hardness qualities.
  • Types HFG8 and HF109 are for heavy-duty applications in sheets as thin as .040”.
  • Grade 8 and property class 10.9 studs meeting 150 ksi/1040 MPa minimum.
  • Recommended for use in steel or HSLA steel sheets HRB (Rockwell “B” Scale) 89 or less and HB (Hardness Brinell) 180 or less.
  • Large head diameter spreads compressive stress on panel.
To be sure that you are getting genuine PEM products, look for the PEM stamp. Studs within the size range of the SAE and ISO specs are also identified with the Grade 8 and 10.9 head markings respectively.

Thread size #10-32 does not have SAE head marking since it is technically not within the size range of the specification.
High tensile strength studs, non flush - HF109, HFG8
High-Strength Studs - Type HFH/HFHS/HFHB 2
Unit of Measure
Items High tensile strength studs, non flush - HF109, HFG8
HFG8-032-8ZI
High-Tensile Strength Studs - Types HFG8™, HF109™ - Unified
High tensile strength studs, non flush - HF109, HFG8
HFG8-0420-8ZI
High-Tensile Strength Studs - Types HFG8™, HF109™ - Unified
High tensile strength studs, non flush - HF109, HFG8
HFG8-032-12ZI
High-Tensile Strength Studs - Types HFG8™, HF109™ - Unified
High tensile strength studs, non flush - HF109, HFG8
HFG8-0420-12ZI
High-Tensile Strength Studs - Types HFG8™, HF109™ - Unified
High tensile strength studs, non flush - HF109, HFG8
HFG8-0518-12ZI
High-Tensile Strength Studs - Types HFG8™, HF109™ - Unified
Thread Size N/A .190-32 (#10-32) N/A .250-20 (1/4-20) N/A .190-32 (#10-32) N/A .250-20 (1/4-20) N/A .313-18 (5/16-18)
Thread Code N/A 032 N/A 0420 N/A 032 N/A 0420 N/A 0518
Length Code N/A 8 N/A 8 N/A 12 N/A 12 N/A 12
Min. Sheet Thickness N/A .040 in N/A .040 in N/A .040 in N/A .040 in N/A .060 in
Hole Size in Sheet + .005 - .000 N/A .190 in N/A .250 in N/A .190 in N/A .250 in N/A .312 in
Max. Hole in Attached Parts N/A .280 in N/A .340 in N/A .280 in N/A .340 in N/A .402 in
L - Length ± .0151 N/A .500 in a1379_1.jpg N/A .500 in a1379_1.jpg N/A .750 in a1379_1.jpg N/A .750 in a1379_1.jpg N/A .750 in a1379_1.jpg
H ± .01 N/A .391 in N/A .507 in N/A .391 in N/A .507 in N/A .645 in
S Max. N/A .105 in N/A .125 in N/A .105 in N/A .125 in N/A .140 in
T Max. N/A .077 in N/A .090 in N/A .077 in N/A .090 in N/A .126 in
Min. Dist. Hole C/L to Edge2 N/A .469 in N/A .709 in N/A .469 in N/A .709 in N/A .827 in
For Use in Sheet Hardness N/A HRB 89 / HB 180 or Less
Thread Specification N/A External, ANSI B1.1, 2A
Fastener Material N/A Heat-Treated Medium Carbon Alloy Steel
Standard Finish N/A Zinc plated per ASTM B633, SC1 (5µm), Type III, colorless
CAD Supplier N/A PennEngineering® (PEM®)
Inventory N/A {0} N/A {0} N/A {0} N/A {0} N/A {0}
  • 1 Other lengths available up to a maximum of 1.5” (unified) on special order.
  • 2 To minimize sheet distortion and maximize product performance, use a centerline-to-edge value greater or equal to the value specified.