Thread Inserts

What Are Thread Inserts?

Thread inserts are devices installed into a prepared hole to create strong, reusable machine threads in materials like aluminum, steel, wood, and plastics. They restore stripped threads, reinforce soft materials, or add threads where none existed. After installation, standard machine screws or bolts can be used repeatedly without damaging the base material.

How Do Thread Inserts Work?

• External form engages the parent material (cutting, knurling, keys, or deformation).
• Internal machine thread matches your fastener (Inch & Metric available).
• Depending on type, the insert is either wound (wire), solid-wall with locking keys, swaged from one side of a panel (rivet nuts), or driven into wood (brass knife-thread).

Correct hole size, installation tool, and torque/load requirements ensure full strength and long service life.

Common Types of Thread Inserts

Helical Wire Thread Inserts

Coiled stainless wire creates a hardened internal thread in softer parent materials. Excellent for repairing stripped holes and improving wear resistance. Available in free-running and screw-locking styles for vibration resistance.

Key-Locking / Solid Threaded Inserts

One-piece solid inserts with keys driven into the parent material to lock the insert against rotation. Ideal for high-vibration, high-load applications (engines, equipment) where a durable, serviceable repair is needed.

Rivet Nuts (Blind Threaded Inserts)

Install from one side of sheet or tubing to add a load-bearing nut where you can’t reach the backside. Offered with round or hex bodies and various head styles in steel, stainless, and aluminum.

Threaded Inserts for Wood

Typically brass with sharp knife threads that bite into hardwoods and softwoods. Provide durable machine threads for knock-down furniture, jigs, and fixtures. Drive styles include internal hex, external slot, and flange types.

Selecting the Right Insert

• Base material: aluminum, mild steel, stainless, plastics, or wood.
• Access: through-hole vs. blind installation (choose rivet nuts for true one-side access).
• Load & vibration: use screw-locking helical or key-locking inserts for vibration-prone joints.
• Corrosion & temperature: pick stainless or coated steel; brass for wood and indoor use.
• Size & thread form: offered in Inch & Metric—match the internal thread to your bolt.
• Hole prep: verify drill/tap size and any countersink/surface requirements in the product specs.

Quick Installation Overviews

Helical Wire Inserts

1. Drill out the damaged threads to the recommended size.
2. Tap with the special STI tap.
3. Install the insert with the driver; set 1/4–1/2 turn below surface; break tang if required.

Key-Locking / Solid Inserts

1. Drill and tap per spec; thread in the insert.
2. Drive the keys down with a punch to lock against rotation.

Rivet Nuts (Blind)

1. Drill the hole to grip-range spec.
2. Use a rivet-nut setter to collapse the insert and clamp it to the parent sheet.

Wood Inserts

1. Drill a pilot hole; add wax for hardwoods if needed.
2. Drive with hex key or slot driver until flush; avoid over-torque.

Applications

• Restoring stripped threads in engines, equipment, and machine tools.
• Adding threads to sheet metal, tubes, and composite panels (blind install).
• Furniture/jigs: durable machine threads in wood for repeat assembly.
• Electronics & enclosures: serviceable threads in plastics and thin walls.

Materials & Finishes (Inch & Metric)

• Stainless steel: corrosion resistance and high-temperature strength.
• Carbon/alloy steel: high strength; plated for corrosion protection.
• Brass: excellent bite and machinability in wood.

Why Buy Your Thread Inserts from Us?

• USA-made options and contractor-trusted brands.
• Inch & Metric coverage with clear drill/tap callouts on product pages.
• Fast shipping and experienced support for installation questions.