Ultimately, the microscopically fine surface finish required throughout very long lengths of stainless steel wire and mandrel is not reflected by the macro level inspection found in most BS5750/ISO9001/9002 systems.
Our inspection procedure is as follows;
1. Goods inward. A visual and dimensional check is made for conformity to specification. In the case of wire (which is supplied die-drawn), this is restricted to the leading tail as it is not viable to re reel and cut sections from the centre of reels. In the case of mandrel material, straightness, diameter and surface condition are made on a standard sampling basis.
2. Mandrel making. Every bar is comprehensively checked for straightness, roundness and surface condition, both in a static test and with the bar in rotation. Defects are corrected where possible or the bar is rejected as unsuitable for its purpose.
3. Wire winding. A further Mandrel check is made by the Winder and the first rod to be wound is given an in-process check by microscope over its entire surface. If passed, winding proceeds with further checks when any parameter is changed, or if the operator entertains doubts. After winding, every Mayer bar is dimensionally checked and the entire surface is given a 100% microscopic examination. Any work with surface defects is returned for re working or scrapped and every reworked rod is re-inspected as above.
4. Plating & Inspection. Where hard-chromium plating is specified, this is carried out to BS5750, ISO9002 and QAS3138/20 standards. After chrome plating, a second 100% microscopic inspection is made of the entire rod surface and any unsuitable rod is rejected and returned to the winding stage.
5. Administrative Controls. Full traceability is provided by a daily work sheet for each member of the production team. Every job and pattern number is recorded, together with rod material type, winding times and speeds, also all polishing, cleaning, inspection, packing and despatch details. Space is provided on every form for operator comment and forms are checked by a senior manager on a daily basis before being placed in a dedicated file for future reference.