SWCHB331

SWCHB331 · JIS G3508

Chemical composition source verified; this does not verify every standard clause, actual supply or measured heat results

Material form

Wire rod

Original record status

Reference transcription of standard

Standard edition

JIS G 3508-2:2005 → JIS G 3508-1:2010

Table / clause

Table 2

Composition

Applicability and limitations

Verification notes

SWCHB331 · JIS G 3508-2-2005

Wire naming, citation relationships, and listed historical version compositions have been verified; Confirm separately the contract-applicable editions of undated references

Material category

Boron steels

Material form

Boron-steel wire for cold heading (SWCHB)

Verification status

Original standard verified

Standard edition

JIS G 3508-1:2005 (material reference in JIS G 3508-2:2005, Clause 4)

Table / clause

Part 1, main-text Table 2 and footnotes; Part 2, main-text Table 1 and note 1—2

PDF page references

3、4、5、6

Unit

Mass fraction (wt%)

Analysis type

Heat analysis

Composition record (conditional branches apply; this is not an unconditional requirement)

Applicability and limitations

Conditional requirement

• Footnote

  Table 5 and Clause 8: dimensions and out-of-roundness

  Source conditions

  Wire diameter d(mm): 0<d≤3, diameter deviation 0/−0.025, out-of-roundness ≤0.013; 3<d≤6，0/−0.030、≤0.015; 6<d≤10，0/−0.036、≤0.018; 10<d≤18，0/−0.043、≤0.022; 18<d≤30，0/−0.070、≤0.035; 30<d≤40，0/−0.100、≤0.050; 40<d≤50，0/−0.150、≤0.070. Out-of-roundness is the difference between the maximum and minimum diameters of the same cross-section; Not ± deviation. >50 is not listed in this table and shall not be extrapolated.

  PDF page references

  5

  Standard edition

  JIS G 3508-2:2005

• Footnote

  Table 6 and Clause 9: general surface-defect depth

  Source conditions

  0<d≤50 mm surface defect depth ≤ 0.10 mm; Harmful scale, corrosion, and other defects harmful to use shall still not exist; depth limits shall not be interpreted as permitting all defects. >50 mm not listed in this table.

  PDF page references

  6

  Standard edition

  JIS G 3508-2:2005

• Footnote

  Table 7: special controls apply only by agreement between both parties

  Source conditions

  Special control subject to agreement between both parties: for 0<d≤15 mm, surface-defect depth ≤0.05 mm.; 15<d≤25 mm≤0.07 mm. >25 mm is not listed in Table 7 and shall not be extrapolated or supplemented with 0; Do not apply the special-control requirements automatically without agreement.. Clauses 10.4 and 10.5 specify the wire diameter and surface inspection methods respectively.

  Subject to agreement

  Yes

  PDF page references

  6

  Standard edition

  JIS G 3508-2:2005

Original condition-branch records

Main-text Table 2 of 2005 gives default composition: B≥0.0008%, Si0.10—0.35%

Only when Table 2, note 2 is adopted by agreement: B≥0.0005%; Si remains within the default range, and any low-Si agreement must be checked separately.

Subject to agreement

Yes

A condition branch must be selected

Verification notes

Mechanical properties applicable to wire process and wire diameter

JIS G 3508-2:2005 · Table 2 Process D, Table 3 Process DA and Notes 1/2; Clause 6 and 10.1/10.2 · PDF pages 4, 6

• Select the actual D/DA process and wire diameter; other processes require agreement between the parties and must not be assumed applicable.
• Rm is an upper tensile-strength limit and Z a lower reduction-of-area limit; Z is not elongation A. 1 N/mm²=1 MPa.
• The entire HRB column is explicitly reference-only in the source; it is not a hardness guarantee.
• For Process D with d≥20 mm, the lower limit of Z is changed from 45 to 40% (reduction of 5); Z is not specified for d≤3 mm; do not fill as 0.
• Note 1 of DA Table 3 refers to Table 2 values. Z at d≥20 mm is withheld pending verification; do not silently change the reference to Table 3 or choose 50/40%.
• Clause 10.1 takes 1 specimen for the same heat, size and heat treatment. Clause 10.2 uses tensile specimen No. 9 under JIS Z2241/Z2201; 9A/9B require agreement. These references are undated; do not invent edition years.
• The decarburization and spheroidization clauses list SWCH30K—SWCH50K, whereas this standard concerns the SWCHB series. Grade applicability remains to be verified; do not automatically apply them to these 12 grades.