ASME B107.18 pdf download ASME STANDARDS COMMITTEE B107 Hand Tools and Accessories
Wre twister pliers shall incorporate a device, which,when actuated, wili cause the plers to rotate abaut itslongitudinal axis. The halves of the plers shall be pernma-nently joined with a through fastener that shali act asthe pivot or fulcrum point of the pliers. A locking device,when engaged, shali hold the handles in a closed posi-tion in sucha marner as to cause the jaws to firmly andsecurely grip and hold stands of lock wire.
wire clearance opening shall be providedbetweenthe two jaws and located between the gripping andcutting areas of the jaws. This opening shal be of a sizeand design which will pernut the user to swiftly andeasily deflect double strands of wire out of the sides ofte jaws and away fron the cutting edges when per-forming continuous (multiple) lock wiring operatians.1he nose design shal be as shown in Figsi 1 through 4and blerd with the radius of the sides of the pliers inaccordance with good conunercial practice. The maxi-mun perinissible opening at the top of the jaws, whenclosed, shall be as shown in Figs. 1 and 2
The raterials used in the marufacture of the pliersshall be such as to produce pliers conforning to therequirements specified herein.
Surfaces shall have a hust preventive treatment andbe essentially free fron pits, nodules, burrs, cracks, andother conditions that would adversely affect the per-formance or safety of the tool.When provided, coatingsshal be adherentsmooth,cortinuous,and frce frormany conditions that would irterfere with their protectivevalue , safety, and function.
Phers shall be narked in a plain and pernanent nan-ner with the manufacturer ‘s nane or with a trademarkof such kanown character that the source of manufactureand country of origin shall be readily determined.Mark-ing shall be as perinanent as the norral life expectancyof the pliers to which it is applied (providing the markedsurface has not been subjected to a fretting or abradlingaction) and be capabie of withstanding the cleaning procedures rormally experiericed during its intended use.
Handles shall have a hardness of 36 HRC to 50 HRC.shall be shaped to provide a comfortable handgrip, andshall be free fron rough edges and sharp corlers.
5.6.1 Hardness. Jaws shail have a hardness of 361IRCto 50 HRC. The gripping portion of the jaws and wirecutter shall be heat treated to a hardness of 56 HRC to64 HRC. Jaw surfaces and edges shal not damage thewie being twisted.
5.6.2 Cushlon 6rip Throat.Cushion grip throat, whenprovided,shailgrip and retain cut wire end.The cushiongrip throat shal be nonmetallc and capable of with-standing noraal use without deteriorating or rubbingoff and shall pass the solvent resistance test in para.6.4.Cushion grip throat shalrenain permanently attachedurder normal use.
s.7 Joint Fastener
The fastener shali have a hardress of 25 HRCto 50HRC.
5.8Spir l Mechanlsm
The spiral mechanism shalt be capable of producinga close, uniform twist in safety wire without binding oior damage to the snrchanism. This mechanism shali bemounted between the handles of the pliers and shall beperLanently affixed to one hardle in such a positionthat the longitudinal axis of the rechanism shall corre-spond to the langitudinal axis of the pliers. The mecha-nismn, when achated, shall cause pliers to rotate aboutits longitudinal axis in its intended directian(s). Eachful actuation of the snechanism shall cause thre pliersto make the following minimum nuonber of completerotations:
aJfor 6 in. (152 mm) size, 2lrotations (with auto-matic retun, 2 rotations)
bfor 9 in. (229 mn) size,3 rotations (with autoraticreturn,215rotations)
fcfor 12 in.(305 mm) size,4 rotations (with automaticreturn.3rotations) (Type 1l Reversibie, 3 rotations)The design of the echanisn shal permit a comfort-able, adequate grip by the operator.