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Taps & Dies
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Thread standards
- M - metric regular thread
- MF - metric fine thread
- G (BSP) - pipe thread
- UNC - American coarse thread
- UNF - American fine thread
- UNEF - amer. Extra fine thread
- UN - amer. with special pitch
- UNS - amer. with special pitch
- BSW - british coarse thread
- BSF - British fine thread
- Tr - trapezoidal thread
- Rd - knuckle thread
- NPT - amer. taper pipe thread
- NPTF - amer. taper pipe thread
- NPS - amer. cyl. pipe thread
- Rc (BSPT) - taper pipe thread
- Rp (BSPP) - cyl. pipe thread
- Vg - valve thread
- BA - brit. assn. Thread
- BSB - BSC - brit. std. thread
- W - taper gas cylinder valves
- Electrical and cable thread
- Bicycle and pedal thread
- Photo and C-Mount Thread
- Mini and nano threads (< 2mm)
- PG - steel conduit thread
- S - buttress thread
- RMS - microscope thread
- MJ, UNJC, UNJF - Aviation
- STI thread (thread inserts)
- Special thread
- Operating tools
- Lubricant
- Thread restoration tools
- Countersink
- Step drills
- Thread gauges
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Thread standards
- BaerCoil/BaerFix
- Drill chucks
- Twist drill bits
Screw taps & Gauges with oversize for wire thread inserts STI thread : Insert Thread (STI Thread: Screw Thread Inserts)
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STI & EG – Thread Inserts Pre-Tap (Oversize) Threads
An insert thread is used only during installation of a wire thread insert. There isn’t a single insert thread profile; instead, there are many variants mapped to common standards such as metric M or UNC. In English these are called STI threads (Screw Thread Insert). At BAER you’ll find the right STI/EG taps for every job.
Everything you need to know about insert threads
Wire thread inserts reinforce newly cut threads or repair damaged ones. To achieve the target nominal size after installation, the hole must be pre‑tapped with an oversize tap – a standard tap would be too small. That’s why specialized STI/EG taps are used.
These taps create a slightly larger receiving thread for the insert; once the insert is installed, the final thread matches the specified size. Designation example: M 2 × 0.4 EG cuts the receiving thread; after installation you obtain M 2 × 0.4.
Insert threads – Our range
Always match the tap to the original thread standard being reinforced or repaired. Our range covers many standards and sizes, manufactured to high precision for reliable results.
Metric insert threads M‑EG and MF‑EG
For metric M (60°) we offer: M‑EG hand taps (one‑pass, hand or machine), M‑EG machine taps (blind/through options), M‑EG combo taps (eliminate separate drilling), and M‑EG thread formers (chipless forming).
For metric fine MF we supply MF‑EG hand taps (HSSG) and MF‑EG machine taps for blind and through holes.
American insert threads UNC‑EG and UNF‑EG
Available as hand taps (also usable manually) and machine taps (faster, material‑flexible), for blind and through holes.
British insert threads BSW‑EG, BSF‑EG and BA‑EG
For BSW and BSF (55°) we offer precise hand taps; for BA‑EG (47.5°) we supply high‑quality HSSG hand taps.
Insert threads for pipe threads G‑Pipe EG and NPT‑EG
For British G (55°) pipe threads we offer G‑Pipe EG HSSG hand taps. For tapered NPT we provide matching NPT‑EG hand taps.
Thread gauges for metric insert threads
Use dedicated M‑EG thread plug gauges to verify the receiving thread (not the finished repaired thread). On request, we can provide in‑house calibration.
Discover tools & accessories for insert threads in the BAER online shop!
Get the correct STI/EG taps and all accessories in the BAER online shop. Our support team is happy to assist by phone or via the contact form.
Do you have any questions? We have the answers!
You'll quickly find the right answers in our FAQ - take a look!