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When two or more thicknesses of plate are rivetted together in 
compression members, the outer row of rivets shall not be more 
than three (8) diameters from the side edge of the plate. 
Hivefc holes must never be spaced more than two and a half 
(2 蚤 ) seldom less than three (8) diameters, nor more than six (6) 
inches from centre to centre. 
All tho rivet; holes of the respective parts of any structure must 
be made to exactly coincide either by drilling the holes full size 
through the connecting portions after being put together, or by sub - 
punching the pieces separately and afterwards reaming the com- 
bined rivet holes to proper size. Iu all cases the burrs must bo 
removed by slightly countersinking tho edges of the liolos. 
All rivets in splice oi. tension joints are to be systematically 
arranged, so that each half of a tension member or splice plate will 
liaye the same uncut area on each siclo of its centre line. 
No rivet is to have a less diameter than tlio thickness of tlio 
thickest plate through which it passes, except in the case of thick 
shoe plates where the holes must bo drilled. 
The least allowable diameter for a rivet is half (^) an inch. 
Eivets must not bo used in tliroct tension. 
Floor B Btiilt 
Track Stringers mul 
Piivle Girders. 
Rivets in Flanges of 
Floor Beann »tc. 
Functions of Web? 
mul Flanges 
Floor beams, built track stringers and plate girders must be 
well stiffened at the points of support and at intervals about equal 
to the depth of tlie beam. 
The stiffeners aro to be of angle iron and are to be placed in 
pairs on opposite sides of the web. They must extend from tlio 
upper leg of the upper flange to the lower leg of the lower flange of 
the beam, being made flush with the other legs of the flanges by 
filling plates. 
In spacing the rivets in the flanges of floor beams, track 
stringers or plate girders, the beam is to be divided into equal por- 
tions of about two (2) feet in length, the stresses in the flanges are 
to be found at the points of division, and there must be enough 
rivets between any consecutive points of division to take up a stress 
equal to tlio resultant of the differcncG of tho stresses at the points 
and the greatest vertical load that can come on this length, provid- 
ing that tlie rivets bo not spaced more closely than two and a half 
(2 士） diameters. 
Iu calculating tlie aimensions of a floor beam, iron track 
stringer or plate girder, tlie web must have sufficient area to take 
up the greatest slioar, and the flanges alone must bo assumed to 
resist the bending. The intensity of working shearing stress is to 
be two (2) tons. 
Limiting Thickness of No web for a floor beam, track stringer or plate girder is to 
have a less thickness than three eigiiths ( 普 ） of an inch. 
