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steel rules

steel rules WItH sHrInK GrAduAtIons Average Shrinkage of Castings (Inches per Foot)
Cast Iron 1/8"
12", 24" Malleable Iron 1/8"
These spring-tempered, satin chrome finished shrink rules are for laying out wood and metal Steel 1/4"
patterns and core boxes for casting metals. Graduated to give shrink allowances directly, they Brass 3/16"
3/16"
Copper
come in 12" and 24" lengths with shrinks from 1/16-3/8" per foot. Aluminum 3/16"
The average shrinkage figures are for metals cast with uniform sections under normal conditions Lead 5/16" Precision rules, straight edges, Parallels
(see table). When using, be sure that the size and shape of castings are considered, since thick Zinc 5/16"
1/32"
Britannia
castings have less shrink and thin castings more shrink than the figures shown. Tin Alloys 1/12"
NOTE: Also see 62 Rule Holder. A very useful tool for patternmakers.

Steel Rules with Shrink Graduations
Cat. No. EDP Length Width x Thickness Shrink Per Foot Graduation
C374-12 51430 12" 1 x 3/64" 1/10" 4R – 8ths, 16ths, Quick-Reading 32nds, 64ths
C370-12 51428 1/8"
C389-12 51473 12" 1 x 3/64" 5/32" 4R – 8ths, 16ths, Quick-Reading 32nds, 64ths
6R – Aircraft Quick-Reading 50ths (.02) Both Edges One Side; Quick-Reading 10ths (.10); Both Edges
C100F-12 50458 12" 1 x 3/64" 3/16"
Opposite Side
C375-12 51432 3/16"
C376-12 51434 7/32"
C377-12 51435 12" 1 x 3/64" 1/4" 4R – 8ths, 16ths, Quick-Reading 32nds, 64ths
C378-12 51437 9/32"
C368-12 51424 5/16"
C374-24 51431 1/10"
C370-24 51429 24" 1-1/4 x 3/64" 1/8" 4R – 8ths, 16ths, Quick-Reading 32nds, 64ths
C389-24 51474 5/32"
6R – Aircraft Quick-Reading 50ths (.02) Both Edges One Side; Quick-Reading 10ths (.10); Both Edges
C100F-24 50459 24" 1-1/4 x 3/64" 3/16"
Opposite Side
C375-24 51433 3/16"
C377-24 51436 24" 1-1/4 x 3/64" 1/4" 4R – 8ths, 16ths, Quick-Reading 32nds, 64ths
C368-24 51425 5/16"

C375-12

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