Steel Tube Handbook - 2018

62 Standard precision seamless steel tubes, cold drawn List of dimensional standards and technical delivery conditions standards EN 10305-1 Steel tubes for precision applications. Part 1: Seamless cold drawn tubes. DIN 2391 Seamless precision steel tubes. Part 1: Dimensions. Part 2: TDC. BS 6323 Seamless and welded steel tubes for automobile, mechanical and general engineering purposes. Part 1: General requirements. Part 4: Specific requirements for cold finished seamless steel tubes. NFA 49-310 Seamless precision tubes for mechanical application. NFA 49-312 Seamless tubes from fine grain steels with improved machinability for mechanical machined parts UNI 7945 Plain end seamless precision steel tubes. ISO 3304 Plain end seamless precision steel tubes - TDC. Stan- dards Dimensions Dimensional standards Dimensional range Tolerance D Tolerance T Lengths Straightness Tube ends EN 10305-1 Table 25/Page 69 Table 26/Page 70 Table 23/Page 68 (Other dimensions upon agreement) See dimensional tables (Inside diameter tolerance is also shown in table) • other tolerances upon agreement • possibility to shift tolerance • by heat treated tubes increasing of tolerance range • ovality included in D tolerances • eccentricity included in T tolerances See notes at page 64 ±10 % min ±0,1 mm (Applied for ordering by: • D x T • d x T) • random 3–7 (9) m • fixed with tolerance ±500 mm • exact with tolerance 0 + upon agreement • max length 18 m – upon agreement Value for exact lengths: L ≤ 0,5 m 0 +2 mm L = 0,5–2 m 0 +3 mm L = 2–5 m 0 +5 mm L = 5–7 (8) m 0 +10 mm L ≥ 7 (8) m agreement   (0 +15 mm) Value in brackets valid for NF A D > 15 mm • total deviation: ReH < 500 MPa 0,0015 L ReH > 500 MPa 0,002 L • local deviation max 3 mm/m D do 15 mm - upon agreement • square cut ends • free from excessive burrs • plain ends • possibility - tol. of D outside values in table (cutting method) • specified end finishing DIN 2391-1 • D > 15 mm 0,25% L • locally 3 mm/m BS 6323/4 NF A 49-310 49-312 Quality range: A - usual tolerances B - reduced tolerances C - cylinder tubes D - special requirements D ≤ 5 mm ±20 % D = 5–8 mm ±15 % D > 8 mm ±10 % min ±0,12 mm UNI 7945 See dimensional tables (Inside diameter tolerance is also shown in table) • other tolerances upon agreement • possibility to shift tolerance • by heat treated tubes ncreasing of tolerance range • ovality included in D tolerances • eccentricity included inT tolerances ±10 % min ±0,1 mm (Applied for ordering by: • D x T • d x T)