C = parts.screw.cheese ('data') returns every cheese head screw in the catalogue as a table, one row for each maker’s article in each size and length, sorted by size and length. C = parts.screw.cheese ('data', NAME) returns those of the thread NAME, such as 'M5', and C = parts.screw.cheese ('data', NAME, L) those of nominal length L too: every article sold as that screw, each with its material or property class and finish. Nothing is built. The catalogue holds slotted screws only.

S = parts.screw.cheese ('solid', NAME, L) builds the screw as a solid.Shape whether or not anyone sells it: any thread of a size the standard defines, any pitch, any length. The bearing face of the head lies on the xy plane, the head above it, the shank below it to z = -L, the slot along the x axis, a hexalobular socket with two lobes on it. S.Name holds the screw’s designation.

Name/Value pairs:

'Drive'

The drive: 'slot', ISO 1207, the default, or 'hexalobular' (alias 'torx'), ISO 14580, whose head is higher. For 'data' it keeps that drive’s screws only; without it every screw comes.

'Maker'

For 'data': only that maker’s articles, such as 'REYHER', in any case.

'ThreadLength'

For 'solid': the length of thread b from the end of the shank, from 0 to L; L threads it to the head. Without it the screw follows ISO 1207 or ISO 14580, which agree: threaded to the head up to 30 long for M3 and smaller and 40 for the rest, and longer ones threaded b min, 25 and 38.

'Detailed'

For 'solid': true builds the head’s side at the standard’s largest taper, 5 degrees, dk across at the bearing face, the fillet of radius r under it, and the thread, cut by solid.Shape.thread; a screw threaded to the head is threaded to within a of it; the hexalobular socket takes its true outline. By default (false) the head is a cylinder, the shank a plain cylinder of diameter d and the hexalobular socket a round hole of its diameter A. Either way the slot is cut n wide, the socket or slot is cut t min deep, and the end is left flat, as rolled.

The table has these variables, each with its unit and its description, which summary (C) lists; lengths are in millimetres:

A screw is designated by the standard’s number when its table defines it: a length of the size’s commercial range, with the thread form the table gives it. Every other screw is custom, its thread length written when shorter than l, as 'Cheese head screw M4 x 60 x 38'.

The catalogue

Articles from REYHER, The Catalogue, edition 2020.04, English, pages 205 to 207 (steel), 513 and 514 (stainless steel) and 630 and 631 (brass, plastic): every article in sizes ISO 1207 defines. Left out: the sizes M1, M1.2 and M1.4. REYHER notes that its stainless screws are partly threaded from 60 long; they are taken here as the standard threads them.

Heads, slots, thread lengths and lengths from ISO 1207:1992, read in IS 1366:2002, and ISO 14580:2011, read in GOST R ISO 14580-2012; screwdriver tips from Wera’s assignment table (catalogue page 53, edition 11/04) to ISO 2380-1.

See also: parts.screw.pan, parts.screw.cap

Source Code: parts.screw.cheese