C = parts.screw.countersunk ('data') returns every countersunk 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.countersunk ('data', NAME) returns those of the thread NAME, such as 'M5', and C = parts.screw.countersunk ('data', NAME, L) those of nominal length L too: every article sold as that screw, each with its drive, property class or material and finish. Nothing is built.

S = parts.screw.countersunk ('solid', NAME, L) builds the screw as a solid.Shape whether or not anyone sells it: any thread of a size its standard defines, any pitch, any length. The top of the head lies on the xy plane, flush with the surface it is sunk into, and the screw runs down to z = -L: the nominal length of a countersunk screw includes its head. A hexagon socket has two corners on the x axis, a hexalobular socket two lobes, a slot lies along it and a cross recess’s wings on the x and y axes. S.Name holds the screw’s designation.

Name/Value pairs:

'Drive'

The drive, which selects the standard: 'hexsocket' (alias 'allen'), ISO 10642, the default; 'slot', ISO 2009; 'crossH' (alias 'phillips') or 'crossZ' (alias 'pozidriv'), ISO 7046; 'hexalobular' (alias 'torx'), ISO 14581. ISO 10642’s head is larger than the one the other three share and its sizes run to M20, theirs to M10, so the drive changes more than the recess. For 'data' it keeps that drive’s screws only; without it every drive comes.

'Class'

For 'solid' with a cross recess: the property class or material, which selects the part of ISO 7046: '4.8', the default, part 1; '8.8', a stainless steel such as 'A2', or a non-ferrous metal ('CU2', 'CU3', 'brass'), part 2. Any other class makes the screw custom. It changes the name only, the two parts sharing their heads.

'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 - k, or L to thread it to the head. Without it the screw follows its standard: threaded to the head up to the length its table gives, longer ones threaded b.

'Detailed'

For 'solid': true also builds the fillet of radius r between the cone and the shank, the true drive (parts.screw.__recess__) and the thread, cut by solid.Shape.thread; a screw threaded to the head is threaded to within k + a of the top, a being 3P for a hexagon socket and 2P for the rest. By default (false) the shank is a plain cylinder of diameter d and the drive the simple one. The end is left flat, as rolled.

The head is the 90 degree cone of its standard, which reaches the theoretical diameter dkt at the top, cut by a cylinder of the actual head diameter dk: the edge, which the standards let be flat or rounded, is that cylinder.

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 its 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. A cross recessed screw takes ISO 7046-1 or ISO 7046-2 by its class.

The catalogue

Articles from REYHER, The Catalogue, edition 2020.04, English, pages 225 to 227, 328, 329, 389 to 394 and 403 (steel), 522, 523, 562 to 564 and 587 to 589 (stainless steel), 634 and 635 (brass, plastic): every article in sizes its standard defines. Left out: the sizes M1 to M1.4, the slotted M12 to M20 (DIN 963’s, not ISO 2009’s), the hexagon socket M22 and M24 (DIN 7991’s, which ISO 10642 replaced) and the hexalobular article 10642.814, whose socket ISO 10642 does not define.

ISO 2009:1994, ISO 7046-1:1994 and ISO 7046-2:1990, heads, recesses, thread lengths and lengths, read in IS 1365:2005 and IS 7485 Parts 1 and 2:2005; ISO 7046-2’s cross recess is its deep series, as part 1’s, and its underhead shoulder is left out. ISO 10642:2004, read in GOST R ISO 10642-2012, with the actual head diameters of Würth’s, SFS’s and Fabory’s article pages. ISO 14581:2013, read in GOST R ISO 14581-2021 and in its official preview, whose heads and sockets agree with fasten.it and fasteners.eu; its thread form from the preview, the same as ISO 2009’s. Cross recesses to ISO 4757 and hexalobular sockets to ISO 10664; screwdriver tips from Wera’s assignment table to ISO 2380-1.

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

Source Code: parts.screw.countersunk