Hobson UNC Socket Set (Grub) Screw, 1/2" / 1 1/2"

The Hobson UNC socket set (grub) screw is a headless socket set (grub) screw with a UNC thread, turned with a hex key in the socket at one end (alloy steel, plain). There are 30 items: #10 to 5/8", in lengths from 3/16" to 2". UNC means Unified National Coarse Thread and TPI means threads per inch.

Where this product is used

• Locking collars, pulleys and gears onto shafts
• Setting the position of a part where a screw head would be in the way
• Securing knobs, handles and bearing collars on spindles
• Workshop jobs where the part is protected by its surroundings
• Knurled cup points resist working loose under vibration

Features

• 30 items: #10 to 5/8"
• Alloy steel, plain
• Length 3/16" to 2"
• Plain (uncoated) steel for dry indoor and machinery use
• Alloy steel construction

Key specifications

Choosing the right option

Choose the thread form first: the grub screw and the tapped hole must match in thread form, diameter and pitch. A grub screw has no head, so the length is the overall length.

These socket set (grub) screws are plain steel, with no coating beyond a light oil film, so they rust quickly in moisture. It suits dry indoor jobs, machinery, and assemblies that will be painted, oiled or enclosed. Where the job is outside or damp, move to hot dip galvanised or 316 stainless. Plain alloy steel socket screws are the normal choice for tooling and machine building, where the parts are usually oiled or enclosed.

UNC is the coarse inch thread form. It does not mate with UNF, so the nut or tapped hole must also be UNC. For load-critical, structural or lifting joints, confirm the fastener against the engineer's specification. Fasteners are not lifting rated unless marked.

Related items: Hobson UNC Socket Set (Grub) Screw, Plain Point, Alloy Steel, 3/4" x 5/8" to 1-1/2", Hobson UNF Socket Set (Grub) Screw, Alloy Steel, Knurled Cup Point, #10 to 1/2" and Hobson UNC Nylon Hex Socket Grub Screw, Natural, 3/8" x 1", Pack of 25.