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Fifty black-oxide alloy-steel socket cap screws, 3/8-16 by 3 inches, hex drive, partial thread, in bulk pack

Kerr Lakeside

Kerr Lakeside 3/8-16 x 3 in. Socket Cap Screw Black Oxide 50 Pieces

SKU CH-6MGZ-M3T90

50 alloy-steel socket cap screws, 3/8-16 UNC by 3 in., black-oxide finish, RC 38-43 hardness, 180,000 psi tensile strength, ASTM A574/ANSI B18.3 compliant

  • Meets ASTM A574 and ANSI B18.3 standards for reliable structural fastening
  • 180,000 psi minimum tensile strength handles extreme loads without failure
  • Black oxide finish resists corrosion while reducing glare during installation
  • Hex socket drive allows secure engagement with standard Allen tools
  • 50-piece pack supplies enough hardware for large or repeated projects

3/8-16 x 3 in. Socket Cap Screws

These Kerr Lakeside socket cap screws come in a 50-piece pack of alloy steel fasteners with a black oxide finish. Each screw measures 3 inches overall with a 1.25-inch partial thread length. They meet ASTM A574 and ANSI B18.3 standards with a Rockwell hardness of RC 38-43.

Ideal for high-strength clamping assemblies

Builders needing coarse UNC threads and hex drive sockets for machine tools, jigs or structural brackets will find the 180000 psi tensile rating suitable. Buyers requiring fully threaded shafts, fine-pitch threads or metric dimensions should look at other fastener types.

1.25 in. partial thread length

The thread extends 1.25 inches from the tip, leaving a smooth shank for the remaining length. This single dimension determines whether the screw can engage the nut or tapped hole while the unthreaded portion spans the joint.

How it compares

Measured against everything we stock in Bits, Hole Saws & Accessory Kits, at today’s prices. Recalculated every night.

Price $29.99
Typical for this category: the median of 5,493 items is $27.99.

Specifications

Product
Brand nameProspect Fastener

Questions about this item

What size hex key fits the 3/8-16 socket cap head?

The drive design is hex for a 3/8 inch socket cap screw; the matching hex key is 5/16 inch, a standard size for this thread diameter.

Which step do installers most often skip when torquing these alloy-steel screws to 180000 psi tensile strength?

They forget to lubricate the threads and bearing surface; without lube the torque reading is low and the clamp force falls short of the RC 38-43 hardness rating.

When should the black oxide finish be touched up or the screws replaced in a corrosive environment?

Inspect the black oxide coating at each service interval; if red rust appears or the finish is worn through, replace the fastener to maintain the 180000 tensile strength.

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