(a) if nails are used, they shall:i. be of a length and size appropriate to the thickness of the assembled pieces;
ii. be sufficiently numerous in relation to the weight being supported;
iii. not be subject to a drawing effect;
iv. be completely driven in, except for double-headed nails in which case the first head shall be completely driven in;
v. have their points flattened should they extend beyond the exterior surface of the last piece assembled; and
vi. be pulled out of any dismantled wood;
(b) when nuts are used, wrenches shall be:i. the appropriate size, to avoid sliding on the head of the nut;
ii. such that while tightening, the elasticity limit of the metal with which the nut is made is not exceeded; and
iii. equipped with a strap to enable the workmen to suspend them from his wrist or belt;
(c) when devices such as clamps or metallic points are utilized, these devices shall:i. be specially designed for this purpose; and
ii. be so fixed as not to slip under the pressure brought to bear upon them.