GMW3224Aug-2002尺寸公差.pdf

WORLDWIDE
ENGINEERING
Material Specification
Metals
GMW3224
STANDARDS
Sheet Steel Thicknesses And Thickness Tolerances
1 Scope
3.1.3 Physical Requirements. Thickness toler-
This specification covers metric sheet steel
ances for coated substrates include the specified
thicknesses and thickness tolerance requirements
coating except for GMAO- Opel (see Deviation
for engineering part drawings. This specification is
Sheet). The specified nominal thicknesses and
applicable to continuous cast, cold or hot rolled
tolerances for uncoated and coated ow carbon
zinc coated or uncoated steel substrates specified
and high strength steel sheet are detailed in
in GMW2 and GMW3032 and supplied as coils or
Tables 1, 2 and 3(Appendix A). The nominal
sheet. Thickness tolerances for coated substrates
thickness tolerance is applicable to measurements
Include the specified coating. Additional require
at any point across the width not less than 40 mm
ments or agreements shall be specified by local
from an edge. Deviations required for individual
business units (e.g, GMNA, Opel ITDC, Saab
GMAO business units are listed in Appendix A
TDC, GM do Brazil, Holden Ltd.
Deviation Sheet-at the end of this specification
3.1.3.1 Business regions may decide, in selective
1.1 Material Description. Subparaaraphs were
istances, to deviate from the tolerances required
not appllcable
in this specification. When this occurs, the
cations. Subparagraphs were not applicabbecifi
1. 2 Cross-reference of Replaced Specifi-
specified tolerance on the drawing shall take
precedence over this specification
3.1.4 Additional Requirements. The rounding-off
1.3 Symbol Not applicable
method shall be used when reporting thickness
1. 4 Typical Application Sheet metal parts con
and thickness tolerances. Reported values shall
sisting of low carbon steel products and zinc coat
be rounded to the nearest 0. 01mm and shall
ed ow carbon steel substrates
utilize the following procedure
1.5 Remarks Not applicable
3.1.4.1 Thickness and thickness tolerances shall
be rounded to the nearest 0.01mm (two decimal
2 References
places). If the third digit is five or above, the
Note: Only the latest approved standards are
second digit shall be rounded to the next highest
number. If the third digit is four or below, the
applicable unless otherwise specified
2. 1 Normative
second digit shall not be changed
ASTM E29
ISO11014-
3.1.4. 2 When employing the rounding method
2.2GM
two or more successive rounding steps should be
GMW2
GMW3032
avoided
GMW3001
GMW3059
3.2 Processing Requirements. Subparagraphs
not applicable
3 Requirements
3.3 Performance Requirements. Subparagraphs
3.1 Requirements on Delivery
not applicable
3.4 Reguirements on other Stages during Life
3.1.1 Chemical Requirements Not applicable
3. 1. 2 Mechanical Requirements Not applicabl
Cycle. Subparagraphs not applicable
4 Manufacturing Process
lot applicable
O Co
ht August 2002 General Motors C
All Rights
August 2002
Originating Department: North American Engineering Standards, Records and Documentation Page 1 of 6