BS 6053:1981 download free.Specification for Outside diameters of conduits for electrical installations and threads for conduits and fittings.
1. Scope
BS 6053 specifies outside diameters of conduits for electrical installations and threads for conduits and littings. It is applicable to all kinds of conduits for electrical installations, independent oliheir material and their naturc (rigid or flcxihle, plain or threaded), taking into consideration all existing conduit entries and th metric threads.
2. Outside diameters
The values specified for outside diamcicrs of conduits for electrical installations and for threads for conduits and fittings arc based on ISO Recommendations R 3. R 161. R 262 and R 286.
rhe tolerances for the conduit diameters are derived from ISO Recommendation R 28ti. Series IT I 3. These values for diameters and tolerances shall be as gi%en in Table I.
3. lb reads
The metric thread shall he chosen according to ISO Recommendation R 6 ( . and 7 II). with 1.5 mm pitch for all diameters.
The mctnc thread shall be as given in Table I.
Details on the thread are given in Table II as well as in I:egure I.
4. Gauges
Gauges for checking ihc maximum outside diameter of conduits having the dimensions specified in (lause 2 shall be as given in Figure 2. It shall be possible to slide the appropriate gauge completely over the conduit, under its own weight.
Gauges for checking the thread for threaded conduits specified in Clause 3 shall be as given in Figure 3. It shall be possible to screw the threadcd gauge into the conduit without undue force. It shall not be possible to pass the gauge. according to Figure I . over the thread without undue force.