Products

Yamamoto Special Steel Co.,LTD

Head Office & Warehouse
ZIP Code: 552-0006
1-4-27 Ishida, Minato-ku, Osaka
TEL: +81 (0)6-6572-8108
FAX:+81 (0)6-6572-8109

Tokyo office
ZIP Code: 105-0004
VORT Shimbashi II 8F,
6-13-12 Shimbashi,
Minato-ku, Tokyo
TEL: +81 (0)3-5843-8760
FAX: +81 (0)3-5843-8776

Seamless pipes standards/manufacturing process list

Outer diameter/Thickness tolerance

Criteria No.	Outer diameter tolerance	Thickness tolerance	Thickness deviation tolerance
Hot finished seamless steel pipes	Less than 50mm/±0.5mm greater or equal 50mm/±1%	Less than 4mm/±0.5mm greater or equal 4mm/±12.5%	20% of the thickness less or equal
Cold finished seamless steel pipes Automatic arc welding pipes Electric resistance welding pipes and Lazer welding pipes.	Less than 30mm/±0.3mm greater or equal 30mm/±1%	Less than 2mm/±0.2mm greater or equal 2mm/±10%

Notes: 1. Thickness deviation is a proportion of the difference between maximum thickness and minimum thickness on the cross section, apart from less than 5.6mm pipes.
2. If the tolerance of outer diameter does not meet the requirement, the outer thickness is not applied.

Mass is calculated by the formula below and is rounded in 3 digits by JIS Z8401.
Nonetheless, it is rounded by kg/m unit when it is over 1000 kg/m.

Signs of the kind	Mass (3) kg	Formula (6)
SUS304TP, SUS304HTP, SUS304LTP, SUS321TP, SUS321HTP	7.93	W=0.02491t(D-t)
SUS309TP, SUS309STP, SUS310TP, SUS310STP, SUS316TP, SUS316HTP, SUS316LTP, SUS316TiTP, SUS317TP, SUS317LTP, SUS347TP, SUS347HTP	7.98	W=0.02507t(D-t)
SUS329J1TP, SUS329J3LTP, SUS329J4LTP	7.8	W=0.02450t(D-t)
SUS405TP, SUS409LTP, SUS444TP	7.75	W=0.02435t(D-t)
SUS430TP, SUS430LXTP, SUS430J1LTP, SUS436LTP	7.7	W=0.02419t(D-t)
SUS836LTP	8.06	W=0.02532t(D-t)
SUS890LTP	8.05	W=0.02529t(D-t)

Notes: (3) Mass is defined as the mass of 1m*1m.
(6) W: Unit mass of the pipe (kg/m)
t: Thickness of the pipe (mm)
D: Diameter of the pipe (mm)
*If there is a need to use the other units, it depends on the agreement between the parties.

Sheet 6 - Outer diameter tolerance

Criteria No.	Diameter mm	Outer diameter tolerance
No.1	Less than 50 greater or equal 50	±0.5mm ±1％
No.2	Less than 50 greater or equal 50	±0.25mm ±0.5%
No.3	Less than 25 greater or equal 25 less than 40 greater or equal 40 less than 50 greater or equal 50 less than 60 greater or equal 60 less than 70 greater or equal 70 less than 80 greater or equal 80 less than 90 greater or equal 90 less than 100 greater than 100	±0.12mm ±0.15mm ±0.18mm ±0.20mm ±0.23mm ±0.25mm ±0.30mm ±0.40mm ±0.50%
No.4	Less than 13 greater or equal 13 less than 25 greater or equal 25 less than 40 greater or equal 40 less than 65 greater or equal 65 less than 90 greater or equal 90 less than 140 greater than 140	±0.25mm ±0.40mm ±0.60mm ±0.80mm ±1.00mm ±1.20mm d)
Notes: a) It does not apply for particular points such as the pipe end's thickness if the tolerance was in the range of Sheet 7. b) Excluding color finished pipes, the criteria 1 is applied to the tolerance of the outer diameter of automatic arc welding pipes, Lazer welding pipes, and electric resistance welding pipes. c) Generally the criteria 4 is applied to the pipes finished with solution treatment. d) In the criteria 4, the tolerance of greater than 140mm in outer diameter depends on the agreement between the parties.

Sheet 7 - Diameter tolerance

Criteria No.	Diameter mm	Outer diameter tolerance
No.1	Less than 4 greater or equal 4	+0.6mm -0.5mm +15％ -12.5%
No.2	Less than 3 greater or equal 3	±0.3mm ±10%
No.3	Less than 2 greater or equal 2	±0.15mm ±8%

Notes: a) See Sheet 6&7 for the tolerance of outer diameter and thickness. Nevertheless, criteria 1 is applied to hot finished seamless pipe. It depends on the agreement between the parties with the other pipes.
b) As long as there is an agreement, the tolerance of pipe length will be +50mm/0mm.