If the power to be transmitted is so much as to render it desirable to have the strength of the laced joint more nearly approach that of the solid belt than is obtainable with a single row of holes, a double row is provided, as shown in [Fig. 2682].

For belts of about 3 inches wide and over, these holes are made as follows: a, b, and c, d, e, about an inch apart and 5⁄8 inch from the line of joint; f, g, h, and i, j, being about 1⁄2 inch behind a, b, and c, d, e, respectively.

For thinner belts the holes may be closer together, and to the edges of the belt the exact distances permissible being closer together as the duty is lighter; but however narrow the width of the belt, it should contain at least two holes on each side of the joint. The sizes of these holes are an important element, since the larger the hole the more the belt is weakened. The following are the sizes of holes employed in the best practice:—

Width of Belt.Size of Punched Hole.
Up to 4 inches1⁄4 inch.
From 4 to 8 inches5⁄16„
From 8 inches upwards3⁄8„

Fig. 2683.

The holes are usually made round, but from the pliability of the lace, which enables it to adapt itself to the form of the hole to a remarkable degree, it is not unusual to preserve the strength of a belt by making an oblong hole, as in [Fig. 2683] at a, or a mere slit, as at b, which, from removing less material from the belt, leaves it to that extent stronger.