BILITOOLS 3/8-16 Thread Repair Kit — 304 Stainless Helicoil Inserts & HSS Drill/Tap Set

BILITOOLS 3/8-16 inch Thread Repair Kit is a complete HSS drill, tap, helicoil insert and installation set designed to restore stripped or damaged SAE threads quickly and reliably.

This professional-grade kit supplies everything needed to repair internal threads in metals, composites and plastics. Built around durable 304 stainless steel thread inserts and high-speed steel (HSS) cutting tools, the set replaces worn threads with a stronger, corrosion-resistant coil and ships organized in a compact iron case for workshop portability.

How does this kit restore stripped threads?

The kit works by enlarging the damaged hole to a precise size, threading the enlarged hole with the included tap, and inserting a stainless steel coil that forms new internal threads. The helicoil insert provides a durable mating surface that resists wear and accepts standard SAE fasteners.

• HSS drill bit sized for 3/8-16 thread preparation
• High-quality tap to cut the new internal thread profile
• 304 stainless helicoil inserts replace damaged threads
• Installation and tang-break tools complete the process

What materials and applications is it suitable for?

This repair kit is formulated for use in a wide range of substrates including steel, aluminum, cast iron, composites and many plastics. It’s commonly used in automotive, plumbing, machinery and marine maintenance where restored thread strength matters.

• Safe for all common metals and many composite materials
• Ideal for cylinder heads, engine blocks, housings and fittings
• Widely used by mechanics, fabricators and maintenance pros

What tools are included and how are they organized?

The set bundles the essential hardware and tools so you can complete a repair without chasing parts. All items are packed into a durable iron case that keeps tools protected and organized between jobs.

• HSS drill and 135° apex angle for efficient cutting
• Matching tap and installation driver for helicoil seating
• 304 stainless thread inserts and a tang-break tool
• Compact iron storage case for transport and on-site use

How do I choose the right size and avoid mistakes?

Confirm the fastener spec (3/8-16 UNF) before purchasing; the set is purpose-built for that SAE size. If you are unsure which repair kit you need, inspect the damaged fastener, measure the original bolt diameter and thread count, or consult the kit's sizing reference image to match the correct drill and tap.

• Verify original thread is 3/8-16 before starting
• Follow the included sizing diagram and torque guidance
• Practice on scrap material if you’re new to helicoil installation

Who this kit is for: This BILITOOLS kit is aimed at mechanics, DIYers, fleet technicians and tradespeople who need a reliable, portable solution to repair stripped SAE threads. If you want a robust stainless-steel insert system with matching HSS cutting tools and a neat carrying case, this set gives you the parts and workflow for repeatable thread restoration on engines, equipment housings and structural components.