Taps
A special tap is a thread-cutting tool made to a specification no catalog covers — a non-standard diameter or pitch, an unusual thread form, a reach or chamfer a stock tap cannot deliver, or a tolerance tighter than commercial classes allow. WESTport manufactures special taps to your blueprint or from a sample part across Unified, metric, ACME, pipe, STI and proprietary thread forms, in right or left hand, from High-Speed Steel, cobalt, powdered metal or carbide. We hold one of the industry's largest inventories of tap blanks, which is why our turnaround on a custom special is measured against shops that have to start from bar stock. Made in the USA and supplying precision manufacturing since 1989.
The WESTport special tap line
Every tap below is built to order. Send a print, a sample, or the thread callout and application, and we will quote the tool that fits it.
- Spiral Flute Taps. Helical flutes lift chips up and out of the hole, which is what makes them the standard answer for blind holes and interrupted holes where chip packing breaks taps. Available in slow helix (25–30°) for general blind-hole work and fast helix (45–50°) for ductile, stringy materials.
- Straight Flute Tandem Taps. Roughing and finishing geometry combined in a single tool, so a thread that would take two passes takes one. Straight flute construction gives maximum rigidity for through-hole and free-machining work.
- Spiral Flute Tandem Taps. The same one-pass roughing-and-finishing design with spiral flutes, for blind holes where you need both the cycle-time saving and reliable chip evacuation.
- Forming Taps. Chipless. Instead of cutting, the tap displaces material to form the thread, producing a stronger thread with a better surface finish and no chips at all — which removes the chip-evacuation problem from blind holes entirely. Best suited to ductile materials.
- Pipe Taps. Special NPT and NPS taps in non-standard dimensions, extended lengths, special chamfers, interrupted threads, and oversize or undersize tolerances. Also available for NPTF, BSPT, BSPP and other pipe forms on request.
- Extension Pipe Taps. An extended shank carries pipe thread geometry into deep or recessed ports — valve bodies, hydraulic manifolds, and any feature set back behind fixturing. Available in 6″, 8″, 10″ and 12″ overall lengths for NPT, NPTF, BSPT, BSPP, ANPT and NPSM.
- Extension Taps. The same reach advantage for straight threads, in pulley, extension and S-shank styles with 2, 3 or 4 flutes, in 6″ through 12″ overall lengths, for deep recesses and counterbored components.
- Long Series Special Taps. An extended threaded section as well as extended overall length, for holes that need thread engagement deeper than a standard tap can produce.
- Short Series Special Taps. Reduced overall length where clearance is the constraint. The shorter tool is also stiffer, which improves control and thread quality in confined fixtures and production equipment.
- Nut Taps. Developed for high-production nut manufacturing. A long chamfer spreads the cut across many teeth to reduce cutting force, and a reduced-diameter shank lets finished nuts accumulate on the tool instead of being cleared each cycle. Extended square drive for durability under continuous production.
- ACME Taps. The 29° trapezoidal ACME form used for rotary-to-linear motion — lead screws, jacks, presses, vises, valves and actuators. ACME taps remove a great deal of material, so they routinely need custom engineering. Multiple-start capability available.
- Popular Special Taps — Inches. The non-standard inch sizes and configurations customers ask for most often, held ready in blank form: 2-56 up through large diameters, in H-limit, STI, spiral point, and multi-flute styles, with taper, plug and bottom chamfers.
- Popular Special Taps — Metrics. The equivalent metric range from M8 upward in 6H and D-limit tolerance classes, including carbide and spiral-point styles, in taper, plug and bottom chamfers.
What we make taps for
Choosing a flute style
Flute geometry decides where the chip goes, and the chip is what determines whether a tap survives a blind hole. This is the shortest route to the right choice.
| Style | Chip behaviour | Best for | Watch for |
|---|---|---|---|
| Straight flute | Chips stay in the flute | Through holes, short chipping materials, maximum rigidity | Chip packing in deep blind holes |
| Spiral point | Pushes chips forward, ahead of the tap | Through holes at speed | Needs somewhere for the chip to exit |
| Spiral flute | Lifts chips back out of the hole | Blind holes, interrupted holes | Less rigid than straight flute |
| Forming | No chips produced | Ductile materials, blind holes, strongest thread | Not suitable for brittle materials |
| Tandem | Depends on flute style chosen | Combining roughing and finishing in one pass | Requires adequate depth clearance |
Materials, coatings and chamfers
Specials are ground from High-Speed Steel, cobalt (M35/M42), powdered metal or solid carbide depending on the workpiece material and production volume, and premium wear-resistant coatings are available on any of them. Chamfer is specified as taper (7–10 threads, easiest entry), plug (3–5 threads, the general-purpose choice) or bottom (1–2 threads, for threading close to the bottom of a blind hole). Flute counts of 2, 3, 4 and 6 are standard, and H-limit or ISO tolerance class is specified with the order.
Industries served
Aerospace & Defense
ANPT pipe threads, STI helical coil inserts, and close-tolerance specials for airframe, engine and actuation hardware.
Energy & Oil and Gas
Large-diameter and heavy-duty specials for valve bodies, wellhead components and pressure equipment.
Automotive
Forming taps and tandems for high-volume production where cycle time and thread strength both matter.
Fluid Power
Extension pipe taps for hydraulic manifolds and deep, recessed ports that standard tooling cannot reach.
Medical Devices
Small-diameter and proprietary-form specials for instruments, implants and fixation hardware.
Job Shops, MRO & Tool Rooms
One-off replacements from a worn tool or a sample part when the original source is gone or the size was never standard.
Why WESTport
- One of the industry's largest tap blank inventories. Most specials start from a blank already on our shelf, not from bar stock — which is where the turnaround advantage comes from.
- Blueprint, sample or callout. Send a print, mail us the worn tool, or just give us the thread and the application. We reverse-engineer specials routinely.
- Right hand and left hand, every form. Unified, metric, ACME, pipe, STI and proprietary geometries, in multiple starts where the application needs it.
- Prototype through production. Single-piece specials and repeat production runs are quoted the same way.
- Made in the USA, supplying precision manufacturing since 1989.
| PART# | PRODUCT NAME | SIZE | TPI | PRICE | SALE PRICE |
