Stainless Steel Seamless Pipe & Tube

Stainless steel seamless pipe is manufactured from a solid round billet heated to 1150–1250°C and rotary-pierced into a hollow mother shell, then finished via cold pilgering (cold rolling) or cold drawing to exact dimensions.

Because it contains no longitudinal or spiral welded seam, seamless pipe eliminates weld decay risks and residual heat-affected zones (HAZ), delivering 20–30% higher allowable working pressures under ASME B31.3 / B31.1 piping codes. TeCarve supplies seamless pipe conforming to ASTM A312, ASTM A213, and EN 10216-5 in grades 304/304L, 316/316L, 321, 310S, 904L, and Duplex 2205.

TeCarve supplies seamless stainless steel pipe from NPS 1/8 in (OD 10.3 mm) to NPS 24 in (OD 610.0 mm) across full ASME/ANSI B36.19M and B36.10M schedules, including Schedule 5S, 10S, 40S/STD, 80S/XS, 160S, and XXS (wall thicknesses from 0.89 mm to 59.54 mm). Precision cold-drawn tubing is also available down to 6.0 mm OD.

Standard delivery lengths are 6.0 m (20 ft) single random; double-random (11.8–12.0 m) and custom precision cut-to-length options (±1.0 mm) are available for direct piping spool prefabrication.

ASTM A312 seamless stainless pipe conforms to the general requirements of ASTM A999 / A999M:

• OD Permissible Variations: NPS 1/8 to 1-1/2 in (+0.40 mm / -0.79 mm, or ±0.40 mm for cold-drawn); NPS 2 to 4 in (±0.79 mm); NPS 5 to 8 in (+1.59 mm / -0.79 mm); NPS 10 to 18 in (+2.38 mm / -0.79 mm); NPS 20 to 24 in (+3.18 mm / -0.79 mm).
• Wall Thickness Limit: Minimum wall at any point must not be more than 12.5% below nominal thickness (-12.5% under; over-thickness governed by weight limits +10% / -3.5% to -5%).
• Straightness & Global Standards: Maximum straightness variation is ≤ 3.2 mm per 3.0 m (1/8 in in 10 ft). International orders can also be manufactured to EN ISO 1127 (D3/T3, D4/T4) or JIS G3459 standards.

Cold Pilgering (Cold Rolling): Uses reciprocating tapered dies and a stationary mandrel to achieve 70–80% cross-sectional reduction per pass. It produces exceptional wall thickness uniformity (wall variations within ±7.5% to ±10%), high concentricity, and low residual stress, making it ideal for high-pressure boilers, nuclear applications, and heat exchanger tubes.

Cold Drawing: Pulls the tube through an outer die and over an internal plug at room temperature. This route delivers tighter outside diameter accuracy (down to ±0.05 mm), a very smooth outer surface finish (Ra ≤ 0.4–0.8 μm), and greater flexibility for non-standard custom dimensions.

Small-Batch MOQ & Lead Time: TeCarve supports flexible 100–300 kg trial orders for standard and custom ASTM A312 seamless piping to assist engineering verification and emergency repairs. In-stock standard sizes dispatch within 7–10 days; custom production runs ship in 10–25 days.

Quality & Testing Documentation: Every production lot is accompanied by an authentic EN 10204 Type 3.1 Mill Test Certificate with full heat-batch traceability. Mandatory quality verification includes hydrostatic testing (up to 20 MPa / 2,900 psi) or eddy current NDT per ASTM A999 / ASTM E426.