KUNGJUER Thread File Set 3-Piece — Metric & SAE Chasers, Carbon Steel with Handle

KUNGJUER 3Pcs Thread File Set is a compact, carbon-steel tool trio designed to restore and re-cut damaged external threads in both metric and SAE sizes.

This three-piece thread chaser collection gives you a practical way to revive worn or flattened threads on bolts, studs, screws and pipe ends without replacing the fastener. Built from heat-treated carbon steel with a black oxide finish, each file covers a range of common pitches so you can tackle metric and SAE threads on automotive, industrial and household workpieces. The set ships with a removable handle and protective end caps for safer use and easier storage.

Which thread sizes are included and why do they matter?

The set contains three distinct thread files that together cover common metric pitches and both UNF and UNC SAE pitches. Having the right pitch is critical: a mismatched tool can further damage threads, while a matched chaser will realign and sharpen the crests and roots for reliable engagement.

• Metric file covers: 0.75mm, 1.00mm, 1.25mm, 1.50mm, 1.75mm, 2.00mm, 2.50mm, 3.00mm.
• SAE UNF file covers: #9, #10, #12, #16, #20, #27, #28, #32.
• SAE UNC file covers: #11, #12, #13, #14, #16, #18, #20, #24.
• Match the tool pitch to the fastener for best results and fewer re-cutting passes.

How tough is the material and will the finish resist corrosion?

Each file is forged from carbon steel and undergoes heat treatment to retain hardness during repeated use. The black oxide coating provides a basic layer of corrosion resistance and reduces light reflection for clearer work in bright shop lights.

• Heat treatment improves wear resistance and edge life under repeated contact.
• Black oxide finish helps resist surface rust when tools are stored correctly.
• Use a light oil for added protection and smoother filing action on long jobs.

How do I use the thread file safely and effectively?

The files are designed to be used with the supplied removable handle and end caps to improve control and reduce risk of injury. Work slowly and align the file with the original thread angle, making light, consistent strokes until the thread profile is restored.

• Secure the fastener or hold it in a vice for controlled strokes.
• Fit the correct pitch on the file to the fastener before starting work.
• Use light oil to lubricate and clear filings; avoid forcing the file.
• Replace protective caps and store dry to prolong tool life.

What kinds of jobs and environments is this set suited for?

This compact set is made for mechanics, technicians and weekend DIYers who regularly service engines, chassis, plumbing, electrical fittings and machinery. It’s portable enough for fieldwork yet durable enough for workshop environments.

• Automotive repairs: bolts, studs, and suspension fasteners.
• Industrial maintenance: machine bolts and assembly hardware.
• Plumbing and piping: external pipe threads and fittings.
• Electrical and construction: conduit threads and fastening hardware.

Who is this for? If you regularly work with threaded fasteners and want a cost-effective way to restore external threads without replacing the part, the KUNGJUER 3Pcs Thread File Set is a practical addition to your toolbox. It’s especially useful for mechanics, maintenance technicians, machine shop operators and serious DIYers who need a portable solution for metric and SAE thread repair. For best results, match the file pitch to the fastener, use steady technique, and keep the tools oiled and capped when not in use.