Threading Tools

Cutwel has been supplying threading tools to precision engineers across the UK and Ireland for over 25 years, and we hold one of the most comprehensive threading ranges on the market, covering every common thread form and production method from a single supplier.

Whether you are cutting or forming, in a blind or through hole, on a CNC machining centre, a lathe or by hand, we have a threading solution built for the job. Our range covers metric coarse and fine, UNC, UNF, BSW, BSF, BA, BSP, NPT and many more.

We stock market leading threading brands such as YG-1, Vargus and Dormer Pramet alongside our own Cutwel Pro range, so you have the choice between premium high performance tooling or lower cost general purpose solutions for those on a budget.

Threading is usually the last operation on a part, which makes it the most expensive place to have a failure. A tap that breaks in a finished component can scrap hours of machining, so tool selection, tapping drill size, holding and cutting data all matter more here than almost anywhere else. If you need help deciding whether tapping, thread milling or thread turning is the right route for your part, our expert technical team can work through it with you. Contact our technical team for support on finding the right threading solution.

Buying from Cutwel also means over 40,000 products held in stock with same-day dispatch on stocked items ordered before 5:30pm, with UK next-day delivery available.

Cutwel supplies a complete range of thread cutting tools and threading tools, covering every common production method and thread standard. Tapping, thread turning, thread milling or cutting by hand, one blind hole or a full production run - we hold the tooling to produce, repair and inspect the thread.

• Machine Taps - A comprehensive machine tap range , with solutions for all materials, applications and budgets. This covers straight flute, spiral point and spiral flute geometries in HSSE and HSS-PM substrates. The range offers something for everyone, whether that be general purpose taps for everyday use, higher performance universal taps that can perform across multiple material groups or dedicated material specific taps for the most challenging applications. The dedicated series cover stainless steel, aluminium and non-ferrous, cast iron and abrasive materials and titanium and titanium alloys, alongside high resistance taps for higher tensile work. The range is completed by synchro rigid taps for synchronised tapping cycles, chip breaker taps for long-chipping materials, and pipe taps in parallel and tapered forms.
• Thread Turning Tools - Single point threading tools for Internal and external screw cutting, including threading holders and laydown inserts in full profile and partial profile forms. Coverage spans metric, UN, Whitworth, BSPT and NPT forms. Internal tooling cuts threads inside a bore or component, while external holders work on the outside diameter.
• Hand Taps - Taper, second and plug taps supplied individually or in sets of three, covering metric coarse and metric fine, UNC, UNF, BSW Whitworth, BSF, BA, BSP (G) and BSPF (G), BSPT and NPT. Essential for maintenance and repair work, legacy threads on older equipment, and finishing a blind hole to depth by hand. Stocked brands include YG-1, Dormer and Presto. Also includes Tap wrenches and accessories to complete the solution.
• Thread and Groove Milling - Solid carbide thread mills and indexable thread milling systems that produce the thread by helical interpolation rather than by purely axial threading. One tool covers a range of diameters at the same pitch and can produce internal and external threads, making thread milling a versatile method for producing threads in CNC machining. The range also includes Simmill multifunctional thread & groove milling tools which can perform multiple operations with one holder. Our range covers all thread forms, diameters, sizes, materials and applications from leading brands Vargus and Simtek.
• Multifunctional Thread and Groove Turning - Replaceable insert systems from leading brands Korloy, Vargus and Simtek which cover threading, grooving, parting and turning from a single holder. Ideal for freeing up turret stations on multi-operation parts and reducing tool changes, particularly on smaller lathes where station count is the limiting factor.
• Dies - Our full range covers all aspects of thread dies including split (adjustable) dies that allow the thread to be adjusted for fit, solid dies for fixed size work, and thread rolling dies for formed external threads. Hexagon die nuts chase and clean up damaged threads with a spanner and die stocks complete the range for threading operations by hand. The range comprises of Cutwel pro dies for economy use to leading brands Dormer Pramet and Josh Boss for reliable high performance work.
• Tap & Die Sets - Matched taps, dies and accessories supplied in a case, covering common sizes in one solution. The practical option for maintenance departments, toolrooms and mobile engineers who need to cover a range of sizes.
• Thread Repair Tools - Thread repair kits and individual thread repair inserts from marketing leading brand Helicoil. Ideal for restoring stripped or damaged threads, along with the oversize repair taps, insertion tools and tang break off tools needed to fit them. In softer parent materials such as aluminium, a steel insert can give a stronger thread than the original, and salvaging a component is almost always cheaper than remaking it.

Thread milling produces the thread by helical interpolation, with a rotating tool smaller than the hole it moves around in, rather than a tap driven straight through on the pitch of the thread.

Start with what happens when the tool fails. A tap that breaks is locked into the thread it has already cut, and on a part with hours of machining in it, that is often a scrap. A thread mill is smaller than the hole, so a broken tool lifts out. On high value components, hardened materials and anything late in the process, that single difference could decide it.

It also covers more ground. One thread mill covers every diameter larger than the tool itself at a given pitch, cuts both internal and external threads, and produces both right hand and left hand threads. A tap does one size, one form and one hand. Thread size is also set by the toolpath rather than the tool, so it can be adjusted through radius compensation to hit a tolerance class without buying anything new. Add lower cutting forces, no lead-in taper in blind holes and short chips cut in open space, and it suits thin walls, small components and long-chipping materials.

Tapping still wins on straightforward, high volume work. In smaller diameters, free-machining materials and repeat production where the part is not expensive to replace, a tap is faster in cycle and cheaper per hole and cold forming roll taps extend that advantage further in ductile materials. Thread milling also requires a CNC machine capable of helical interpolation, so it is not an option on manual equipment.

We supply both routes. Our solid carbide thread mills cover smaller diameters and finer pitches, while indexable thread milling systems are the economical choice on larger diameters. Scrap risk and cost per part, not cost per tool, are the numbers that decide it - our technical team can work that comparison through against your part, material and machine. Call 01924 869 615 to discuss it.

The difference is how the tap is driven and what happens to the chips. It is not a question of which cuts a better thread. Both produce a thread to standard when used correctly.

Hand taps are turned by hand in a tap wrench, usually as a set of three. The taper tap has a long lead of around seven to ten threads to start the hole square, the second tap has around three to five and does most of the cutting, and the plug tap has a short lead of one to two threads to finish a blind hole close to the bottom. They have straight flutes, so chips are not pushed anywhere - the operator backs the tap off to break them. That makes them the right choice for maintenance and repair work, legacy threads on older equipment, and anywhere you want to feel the cut before committing to it.

Machine taps are driven under power in a CNC machine, a mill, a drilling machine or a tapping arm, and cut the full thread in a single pass. The flute geometry does the chip control:

• Spiral point taps push the chip forwards, ahead of the tap. Use in through holes, where the chip clears out of the bottom.
• Spiral flute taps pull the chip backwards, out of the hole behind the tap. Use in blind holes, where there is nowhere else for it to go.
• Straight flute machine taps suit short-chipping materials such as cast iron and brass, where the chip breaks up on its own.
• Cold forming roll taps produce no chip at all, because the thread is displaced rather than cut. Suited to ductile materials, and they require a larger tapping drill than a cutting tap of the same size.

If the job is on a machine, use a machine tap. Hand taps can be run under power at low speed, but they have no chip control geometry, so it is a compromise. If the job is on the bench, in situ, or on an awkward existing hole, use a hand tap.

Where people get caught out is the tapping drill size and the holding. A cutting tap and a roll tap of the same thread need different hole sizes, and rigid tapping needs a synchronised cycle or a compensating tap chuck to avoid pulling the thread. If you are unsure which route your job needs, our technical team will talk it through.

Cutwel supplies threading tools to precision engineers across aerospace, automotive, medical, energy, maintenance and general subcontract machining. Every sector throws up a different mix of material and thread standard, so the method and the tool change with it.

• Aerospace and defence: Titanium, nickel superalloys and aerospace aluminium in airframe structures, engine components and fastener locations. Titanium series taps and thread mills handle the heat and work hardening, while roll taps suit aluminium structures where a chip-free blind hole matters. Thread repair inserts are widely used here, providing a steel thread in a light alloy component. Scrap risk drives the tool choice, because the material is expensive long before you thread it.
• Automotive and motorsport: Cast iron, aluminium alloys and hardened steel in engine and gearbox housings, chassis parts and volume batch work. Roll taps give the tool life and cycle time on aluminium, cast iron series taps handle the abrasion, and synchro rigid taps suit synchronised cycles on modern machining centres, where cost per hole across the batch is what gets measured.
• Medical: Stainless, titanium, cobalt chrome and engineering plastics in implants, instruments and orthopaedic components. Small diameter threads, fine pitches and tight tolerance classes, where solid carbide thread mills let the size be corrected on the control instead of changing tools. Accuracy matters more than cycle time here.
• Oil, gas and power generation: Duplex and super duplex stainless, nickel alloys and hardened steels in valve bodies, subsea components and turbine parts. Thread turning covers the larger diameters and coarse pitches these parts carry, pipe taps and BSPT and NPT tooling cover the sealing threads, and stainless series taps resist the work hardening. Downtime on these parts costs far more than the tooling does.
• Maintenance, repair and fabrication: Mixed and unknown materials, in situ work and legacy equipment. Hand taps across metric, UNC, UNF, BSW, BSF, BA and BSP, dies and hexagon die nuts for chasing damaged threads, and thread repair kits for salvaging stripped holes. Tap and die sets suit this work because the next job is rarely the same standard as the last one.
• General and precision subcontract: Mixed materials and short runs, one-off through to batch. General purpose and high performance universal taps cover most work from one tool rather than stocking a series per material, with thread turning and thread milling covering the sizes and forms a tap cannot. Stock availability and range breadth matter as much as the tool itself.

Whatever the sector, our technical team can match the method, geometry and thread standard to your material and machine. Speak to us about your application or browse the threading range online.

Yes. The website carries the popular ranges from our core threading brands, but we have access to a far wider range than appears in the online catalogue. Behind it we have a supply network covering more manufacturers, sizes, thread forms, tolerance classes, coatings and specialist tools that we can source to order.

That matters more in threading than in most categories, because a thread is defined by a standard, not a diameter. Non-preferred pitches, left hand threads, oversize and undersize tolerance classes, ACME and trapezoidal forms, API and other sealing threads, and long shank or extension taps for deep or restricted access are all things we source to order.

If you cannot find what you are looking for, please contact our technical team who will be happy to help find the exact threading tool you require. We can also advise on alternative parts should you require a brand that we do not supply. Our team can cross reference this and quote our exact alternative for you.

Send us your enquiry online or speak to the technical team about what you need.

Cutting data is published on the product page for each series, as a downloadable PDF.

1. Search the series or part number in the search bar, or navigate through Threading Tools to the category you need.
2. Open the series page. Each page covers the whole series, so one page holds every size in that range.
3. Click Download Cutting Data, under the key features. Download Product PDF next to it gives you the dimensional drawing and full size listing.
4. Check the coloured squares above the links. These are the ISO material groups the tool is rated for - P for steel, M for stainless, K for cast iron, N for non-ferrous, S for heat resistant alloys and titanium, and H for hardened material.

Every sheet works the same way. Find your series code along the top, find your material down the left hand side, then read across to where the two meet. Materials are broken down by condition with a hardness figure in HB or HRc alongside, so match the condition as well as the name. Where a cell is blank, that series is not recommended for the material.

What the sheet gives you depends on the tool. Tap data is usually a single figure, Vc in metres per minute, because a tap is fed at the pitch of the thread it is cutting and the feed is therefore fixed by the thread itself. Thread mill and thread turning sheets carry more, including feed and the number of passes. Hand taps and dies are turned by feel and have no published data.

The figures assume a rigid setup in good condition. On a lighter machine, a deeper hole or a marginal coolant supply, start at the lower end of the range and work up.

One more figure is worth knowing about. On machine and hand tap listings, the drill diameter column gives the tapping drill size for each thread in the series, which removes the most common cause of tap breakage.

If you cannot find data for a series or would like to discuss the right parameters for your material and machine, call our expert technical team on 01924 869 615.

Yes. Alongside our standard threading range, we supply special and bespoke threading tools made to your requirements. We work with UK and overseas manufacturers who can handle anything from a simple modification to an existing tool through to a design from scratch.

We get more special requests in threading than in most categories, because so much of it comes down to the thread standard on the drawing. Common requests include non-standard and non-preferred pitches, oversize and undersize tolerance classes, left hand threads, ACME, trapezoidal, buttress and API forms, long shank and extension taps for deep or restricted access, and multi-form tools that combine threading with another feature in one pass.

The service is not limited to taps. We also supply custom thread mills, thread turning inserts and holders, dies, and the thread gauges to verify the finished thread, so a whole operation can be specified in one go.

Our technical team will take you from concept and tool design through to machining the final part, advising on the best route and working with the manufacturer to keep delivery on schedule. In many cases they will also tell you when a standard tool or a modified standard will do the job faster and cheaper than a full special.

To start an enquiry, call the specials team on 01924 869 665, email specials@cutwel.net, or use the enquiry form on our Custom Threading Tools page. Send your drawing, the material and the thread you need to produce, and we will come back with the options.

Yes. We stock tooling across metric and imperial thread standards, including the older British forms that are still found throughout UK engineering.

Metric coarse and metric fine, in machine taps, hand taps, thread mills, thread turning inserts and dies. Metric coarse covers most of the general engineering work, while metric fine is used where a finer pitch gives better adjustment, more resistance to vibration or greater strength in a thin wall.

UNC and UNF across taps, dies and thread turning, covering American and international work along with a large amount of legacy machinery still in service in the UK.

BSW Whitworth, BSF and BA remain in daily use across maintenance, restoration, agricultural and older industrial equipment, and they are frequently the reason a job stalls when a supplier only carries metric.

BSP parallel and BSPF (G), BSPT taper and NPT, covering hydraulic, pneumatic and fluid handling work where the thread has to seal as well as fasten. Pipe taps and thread turning inserts cover the same forms on CNC.

Thread milling gives you further flexibility within a given thread form. Because the profile is produced by the toolpath rather than the tool, one thread mill covers every diameter larger than itself at the same pitch, internal and external. The tool is still tied to the thread form, so a 60 degree cutter covers metric and Unified but not the 55 degree Whitworth and BSP forms.

Beyond these, ACME, trapezoidal, buttress and API forms are available as specials. See Custom Threading Tools or contact our technical team.

Yes. Our technical team are time-served engineers who spend their days on exactly these questions, so you are not paying for advice or waiting on a callback from a manufacturer.

For tool selection, we match the method, geometry, substrate and coating to your material, your thread standard and the machine you are running. That includes whether tapping, thread milling or thread turning is the right route in the first place, and the honest answer when the tool you are asking for is not the one you need.

For problems on the machine, we work back from what the tool is doing to why. Broken taps, oversize or undersize threads, poor finish, chip packing in blind holes, torn flanks and short tool life usually come down to tapping drill size, cutting data, holding or coolant, not the tap itself, so a different tool is not always the answer.

We can also review a threading operation you are already running, to see where cycle time or cost per part can be taken out. On repeat work, moving from a cutting tap to a cold forming roll tap, or from tapping to thread milling on high value parts, often makes a bigger difference than changing brand.

Call 01924 869 615, or send us a drawing and a description of what the tool is doing.