Wexmar provides custom fastener machining for special bolts, studs, shoulder screws, clevis pins, nuts and washers that cannot be pulled from a catalog. Our shop in Canastota, New York produces CNC machined fasteners on Swiss-type machines and CNC lathes in carbon steel, stainless, titanium and high-nickel alloys. We are a direct custom fastener manufacturer for low and medium volumes, and every quote is confirmed by a human estimator.
What custom fasteners do and who buys them
A special fastener is usually specified because a standard part cannot meet a length, grip, head form, material or load requirement. It must carry clamp load, locate a part, or both. Typical buyers include:
- Industrial OEMs needing shoulder bolts, special-length studs and eye bolts
- Fastener distributors sourcing specials and short runs for their customers
- Pump, valve and fluid power builders needing stainless and nickel alloy studs
- Defense, government and aerospace programs with build-to-print fasteners, often requiring material traceability
How our custom fastener machining works
Swiss machining
Fasteners up to 32 mm diameter run on our four Maier MLK-32 Swiss-type machines with FMB bar feeders. Long studs, shoulder screws and pins are turned with the guide bushing supporting the cut, then threaded, slotted, cross drilled and parted off in one cycle. Swiss runs can operate lights-out. See Swiss machining.
CNC lathes with live tooling
Larger bolts, nuts and heavy studs run on our Mazak and Doosan lathes, up to the Mazak Nexus 450-II for large diameters. Live tooling mills hex heads, drills safety wire holes and cuts cotter pin holes. The Multiplex 6300Y machines both ends of a stud complete.
Horizontal milling
Fasteners with non-round features, such as T-bolts, flattened eye bolts and special nuts with flanges or slots, can finish on our Mazak horizontal machining centers.
Typical fastener materials
- Alloy steels such as 4140 and 4340, often heat treated to a specified hardness
- 300-series, 17-4 PH and Nitronic 50 stainless for corrosion resistance and galling resistance
- Inconel 718, Monel and Hastelloy for heat and corrosive service
- Titanium for strength-to-weight applications
- Brass, bronze, aluminum and engineered plastics for non-structural or insulated fasteners
DFARS 252.225-7009 specialty-metals-compliant sourcing is available for defense work.
Critical features and how we hold them
- Shoulder diameter: held as a locating fit, turned or centerless ground where tight tolerance and finish are needed.
- Thread class: single-point cut and gaged to class 2A or 3A, or UNJ with controlled root radius.
- Head to shank squareness: the underhead face is cut in the same setup as the shank, and underhead fillets are formed to print.
- Hex and wrench features: milled with live tooling for consistent across-flats dimension.
- Cross holes: safety wire and cotter holes are positioned from the head datum.
Typical tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Shoulder or pin diameter | +/-0.0005 in | +/-0.0002 in (ground) |
| External thread | Class 2A | Class 3A or UNJ-3A |
| Overall length | +/-0.010 in | +/-0.002 in |
| Hex across flats | +/-0.003 in | +/-0.001 in |
| Head to shank squareness | 0.002 in | 0.0005 in |
| Shank finish | 63 Ra | 16 Ra (centerless ground) |
Values are typical and depend on length, diameter and material. The quote confirms what we will hold on each feature.
Machined versus headed fasteners
High-volume standard fasteners are usually cold headed and roll threaded. Machining makes sense when quantities are in the tens to low thousands, when the material is difficult to head (Inconel, titanium, Nitronic 50), when the part has shoulders, cross holes or tight diameters, or when lead time matters more than unit cost. We can advise at the quote stage whether a part is a good fit for machining.
Secondary operations
Heat treat, thread rolling, plating, black oxide, passivation and dry-film lubricant coatings are completed through qualified outside processors, with processor certs returned with the parts. Head marking can be machined in-house or arranged outside.
Quantity patterns
Custom fastener orders commonly range from 25 to 5,000 pieces, often as repeat blanket releases. Heat-lot traceability can be carried from bar stock through finished parts. See also threaded components.
Inspection
Threads are gaged to class, shoulders are measured with micrometers and our Brown and Sharpe CMMs, and underhead fillets and thread form are checked on the Mitsubishi optical comparator. FAI in AS9102 format, material certs and heat-lot traceability are available.
Getting a quote
Send the drawing or specification, material, finish and quantity. You can upload a drawing for an instant estimate, and an estimator will confirm price and lead time. Call (315) 400-2654 to discuss a special fastener.