C = parts.screw.set ('data') returns every set screw in the catalogue as a table, one row for each maker’s article in each size and length, sorted by size, pitch and length. C = parts.screw.set ('data', NAME) returns those of the thread NAME, such as 'M6' or 'M8x1', and C = parts.screw.set ('data', NAME, L) those of nominal length L too: every article sold as that screw, each with its point, property class and finish. Nothing is built.

S = parts.screw.set ('solid', NAME, L) builds the screw as a solid.Shape whether or not anyone sells it: any thread of a size the standards define, any pitch, any length its point fits in. NAME names a coarse thread by its diameter, 'M6', or any pitch, as 'M8x1'. The socket end lies on the xy plane, the screw below it to z = -L, the socket sunk into it with two of its corners on the x axis. S.Name holds the screw’s designation.

Name/Value pairs:

'Point'

The point, which selects the standard: 'flat', ISO 4026, the default; 'cone', ISO 4027; 'dog', ISO 4028; 'cup', ISO 4029. For 'data' it keeps that point’s screws only; without it every point comes.

'Maker'

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

'Detailed'

For 'solid': true cuts the thread, by solid.Shape.thread, from the socket end to the point. By default (false) the screw is a plain cylinder of diameter d.

Each standard gives a short screw, of a nominal length up to its table’s shaded lengths, a shallower socket and wider angles than a long one. Either way the solid takes the standard’s largest point diameters and dog length and its smallest socket depth t, and chamfers the socket end from the thread’s minor diameter, d - 1.0825 P, at 90 degrees included, 120 for a short screw. The points:

flat

A flat end dp across, chamfered at 45 degrees.

cone

A cone of 90 degrees included, 120 for a short screw, its tip cut flat dt across.

dog

A cylinder dp across and z long, short or long as the screw, reached from the thread by a 45 degree chamfer; the slight radius at its end is left out.

cup

A 45 degree chamfer down to an edge dz across, round a conical cup of 120 degrees.

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 the standard’s table defines it: a coarse thread and a length of the table’s commercial range. The four standards share one denomination, so a custom screw names its point instead, as 'Hexagon socket set screw with cone point M8x1 x 20'.

The catalogue

Articles from REYHER, The Catalogue, edition 2020.04, English, pages 272 to 278 (steel) and 541 to 544 (stainless steel): every article in sizes the standards define, M1.6 to M24, fine pitches included. Left out: the size M14, which none of the four standards defines.

Sockets, points and lengths from ISO 4026, 4027, 4028 and 4029, all 2003, Table 1 and Figure 1 of each, read in IS 6094 Parts 1 to 4:2006, which agree with REYHER’s Technical Information (2019, TI-20) but where REYHER drops a digit of t at M1.6 and M2.

See also: parts.screw.cap

Source Code: parts.screw.set