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Starrett screw pitch gages are among the most useful tools in any mechanics' tool box. They quickly determine the pitch of various threads. These gages consist of a substantial steel case with a number of folding leaves at both ends, each leaf having teeth corresponding to a definite pitch, marked on each leaf.
Starrett screw pitch gages are available in a wide range of sizes with different numbers of leaves in various pitch ranges with which to gage.
- V, Unified, American National 60° threads
- Whitworth Standard 55° threads
- International Metric Standard 60° threads
- English and metric threads are similar in form, but English threads are described in threads per inch and metric threads by the distance from one crest to the next.
All Starrett screw pitch gages (except No. 473 and 476, which have a positive stop design) feature a locking device at both ends of the case, so leaves can be securely locked in position for use. Leaves on all gages have a special narrow design, permitting checking internal threads in nuts, etc., as well as external threads.
Various types of Starrett screw pitch gages are illustrated on the following pages, with complete specifications.
Formulas
Am. Nat.
d=D – 1.299
............N
V Thread
d=D – 1.732
............N
D = Outside diameter of tap
d = Bottom diameter of tap
N = Number of threads per inch
Starrett English and Metric Screw Pitch Gages – No. 6, 155, 472, 473, 474, 484 Series
Range: 2 1/4-84 Pitches (Inch)
Range: 0.25-11.5 Pitches (Millimeter)
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Catalog No.
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EDP No.
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Description
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List Price
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6
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50035
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60° Threads, 30 Leaves, 4-42 TPI
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29.50
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155
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50588
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60° Threads, 27 Leaves, 2 1/4-28 TPI
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42.00
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472
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52484
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60° Threads, 51 Leaves, 4-84 TPI
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56.00
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473
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52485
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60° Threads, 30 Leaves, 6-80 TPI
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30.00
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474
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52486
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60° Threads, 28 Leaves, 4-80 TPI
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30.00
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484
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67447
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60° Threads, 28 Leaves, 3 1/2-36 TPI
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30.00
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J.W. Donchin Co.
 Ph: 773-261-2182 • Fax: 773-261-2867 • Email: sales@jwdonchin.com
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