20# 45# 16Mn Inch or metric diameter honed tubing GB/T3639-2000 Standard

material

hardness(HB)

thickness(mm)

internal diameter(mm)

20#/16Mn

200-220

2.5~5.5

38.1 (1\")

3~6.25

44.45 (1.75\")

4~6.5

50.8 (2\")

4.5~7

63.5 (2.5\")

4.5~7.5

76.2 (3\")

5~9.5

88.9 (3.5\")

5~10.5

101.6 (4\")

6~12

114.3 (4.5\")

6.5~13

127 (5\")

6.5~14.5

139.7 (5.5\")

6.5~17

152.4 (6\")

End?Shape

Beveled?end,?plain?end,?vanished,?or?adding?plastic?caps?to?protect?the?two?ends?as?

per?customer\'s?requirements

Surface?
Treatment
?

Oiled,?Galvanized,?Phosphate Plastic injection etc
?

Technique?

Cold?drawn

Application

1.?Automotive?and?mechanical?pipes

2.?Petroleum?cracking?pipes

3.?High?Pressure?Boiler?Pipe

4.?Low?and?middle?pressure?fluid?transportation?pipeline

5.?Chemical?fertilizer?equipment?pipes

6.?Heat?exchange pipes

Delivery
Conditions
?

1.?BK?(+C)?

No?heat?treatment?after?last?cold?forming?process.

2.?BKW?(+LC)

After?last?heat?treatment?there?is?a?light?finishing?pass?.

3.?BKS?(+SR)

After?the?final?cold?forming?process?the?tubes?are?stress?relieve?annealed.

4.?GBK?(+A)

After?the?final?cold?forming?process?the?tubes?are?annealed?in?a?controlled?

atmosphere.

5.?NBK?(+N)

After?the?final?cold?forming?process?the?tubes?are?annealed?above?the

?upper?transformation?point?in?a controlled atmosphere.?

Package

1.?Bundle?Packing.

2.According to the customer request
?

3.?Wrapped?in?waterproof?paper.

4.?Sackcloth?with?several?steel?strips.

5.?Pack?in?heavy?boxes.