The Tenacity of Good New Belt Leather varies from 3,000 lb. to 5,000 lb. per square inch of sectional area.

The Coefficient of Friction between ordinary belting and cast-iron pulleys is about .423.

The Thickness of Belts varies from three-sixteenths to five-sixteenths of an inch, or an average of one-fourth of an inch.

Tenacity Of Riveting And Lacing

The ultimate tenacity of good single leather belting may be taken at about 1,000 lb. per inch in width; the corresponding strength of a riveted joint being about 400 lb., a butt laced joint about 250 lb., and an ordinary overlap laced joint 470 lb. It is not customary, however, to allow an effective strain of more than one-fourth these amounts.

Working Stress Of Belts

The following are the effective working stresses allowed for the different kinds and thicknesses of belts referred to in the table of powers.

Ordinary single belts,

50 1b.

Light double belts,

70 1b.

Heavy double belts,

90 1b.

Link belts, ⅜ in. thick,

42 1b.

"

"

in.

"

48 lb.

"

"

⅝ in.

"

57 1b.

"

"

in.

"

66 1b.

"

"

⅞ in.

"

78 1b.

"

"

1 in.

"

90 1b.

Speed Of Belting

On ordinary shop line shafts the velocity of the belts varies from 1,000 ft. to 1,500 ft. per minute. Lathe belts vary from 1,500 ft. to 3,000 ft. per minute.

Stress On Shafting

The cross stress on shafting arising from the sum of the tension on the two sides of the belt may be taken at 90 lb. per inch in width. - Practical Electrical Engineers' Pocket Book and Diary.

Transmission Of Power By Belting 259

- From Haeder & Powles' Handbook on the Steam Engine.

Transmission Of Power By Belting 260

- From Haeder & Powles' Handbook on the Steam Engine.