Specialty alloys are the metals you reach for when stainless isn't enough: sour oilfield service, high heat, seawater, or the best strength for the weight. They're expensive, often hard to find in small amounts, and almost always need paperwork. We source nickel alloys, titanium and precipitation-hardening stainless for Texas machine shops and oilfield fabricators, in the quantities a job actually needs, with certs and traceability.
What shops use specialty alloys for
Alloy 625 resists corrosion in seawater, acids and sour gas and welds well, so it shows up in oilfield parts, offshore fittings and overlay work. Alloy 718 is age hardenable to very high strength and holds it at high temperature, the common choice for downhole tools, fasteners and turbine-type parts. Alloy 400, a nickel-copper grade, handles seawater and brine in pump shafts and marine hardware. Titanium Grade 2 is commercially pure and corrosion resistant; Grade 5 (6Al-4V) is the strong one, with steel-like strength at a little over half the weight. 17-4PH stainless hardens with a simple low-temperature age and is common in valve, pump and aerospace parts.
Small orders are normal here. One bar end for a prototype, a few blanks for a repair part, a short piece of plate. We quote them.
Common specialty grades
| Grade | Key traits | Typical uses |
|---|---|---|
| Alloy 625 (UNS N06625) | Nickel-chromium-moly, outstanding corrosion resistance, weldable | Oilfield and offshore parts, seawater, chemical service |
| Alloy 718 (UNS N07718) | Age hardenable, very high strength to high temperature | Downhole tools, high-strength fasteners, hot-section parts |
| Alloy 400 (UNS N04400) | Nickel-copper, resists seawater and brine | Pump shafts, marine hardware, valves |
| Titanium Grade 2 | Commercially pure, very corrosion resistant, formable | Chemical and marine parts, heat exchangers |
| Titanium Grade 5 (6Al-4V) | High strength, light, heat treatable | Aerospace, medical-style and motorsport parts |
| 17-4PH (UNS S17400) | Precipitation-hardening stainless, hardened by aging (H900 to H1150) | Valve and pump parts, shafts, aerospace fittings |
Forms available
Round bar is the most common form across all of these, from small diameters for pins and fasteners up to large bar for downhole tools. Sheet and plate are available in 625, Grade 2 and Grade 5 titanium, and 17-4. Welded and weld-free tube and pipe come in nickel alloys and titanium. Condition matters as much as grade: 718 comes solution annealed or aged, and 17-4 comes in Condition A or already aged to a specific H condition. Name the condition and spec on the RFQ.
Typical size ranges
| Form | Commonly available range |
|---|---|
| Round bar (nickel alloys, 17-4) | 1/4" to about 10" diameter |
| Titanium round bar | 1/8" to about 6" diameter |
| Sheet | 0.020" to 0.187" thick |
| Plate | 3/16" to about 4" thick, cut to size |
| Tube and pipe | Small OD tubing through common NPS pipe sizes in standard schedules |
Commonly available ranges. Ask for anything outside them.
Cutting options for specialty alloys
Most orders are bar pieces, saw cut to length. These alloys saw slowly and work harden, so a clean cut at the source is worth it. Plate and sheet blanks go to waterjet, which leaves no heat-affected zone, the right choice for nickel alloys and titanium that will be machined or need their properties intact. Titanium sheet can be laser cut under inert gas, but plasma is a poor fit: it leaves a brittle, oxidized edge on titanium that has to come off.
Certs and traceability
Assume you'll need them. A specialty-alloy MTR shows the heat, chemistry, condition, mechanical results and the spec, such as ASTM B446 or AMS 5666 for 625 bar, AMS 5662 or 5663 for 718 bar, ASTM B348 for titanium bar, and ASTM A564 or AMS 5643 for 17-4 bar. Sour-service work under NACE MR0175 / ISO 15156 needs the material and hardness to comply. Tell us the spec and condition up front, and ask for the heat number on every cut piece. See mill certs and traceability.