21.040 - Screw threads

This document specifies the basic dimensions of ISO metric trapezoidal screw threads in accordance with ISO 2902. The values refer to the design profiles in accordance with ISO 2901. This document is chiefly applicable to traversing threads for traversing motion on machines, tools, etc. It can also be used for fastening threads.

This document specifies dimensions and tolerances for taper screw threads of nominal diameter
17,4 mm (designated as 17E) and 25,8 mm (designated as 25E) used for the connection of valves to gas
cylinders.
It does not cover the connection requirements for
— mechanical strength,
— gas tightness, and
— capability of repeated assembly and dismounting operations.
Gauge inspection is covered by ISO 11363-2.

This document specifies types, dimensions and principles of use of gauges, to be used in conjunction
with the taper threads specified in ISO 11363-1 (i.e. 17E and 25E threads).
It provides examples of calculations for thread gauge dimensions on the large end diameter (Annex A)
and draws attention to the limitations of the gauging system specified (Annex B).

ISO 11363-1:2018 specifies dimensions and tolerances for taper screw threads of nominal diameter 17,4 mm (designated as 17E) and 25,8 mm (designated as 25E) used for the connection of valves to gas cylinders.
ISO 11363-1:2018 does not cover the connection requirements for
- mechanical strength,
- gas tightness, and
- capability of repeated assembly and dismounting operations.
Gauge inspection is covered by ISO 11363‑2.

ISO 11363-2:2017 specifies types, dimensions and principles of use of gauges, to be used in conjunction with the taper threads specified in ISO 11363-1 (i.e. 17E and 25E threads).
It provides examples of calculations for thread gauge dimensions on the large end diameter (Annex A) and draws attention to the limitations of the gauging system specified (Annex B).

This International Standard is a supplement to ISO 2568 and ISO 4230 and specifies the dimensions of
hand- and machine-operated circular screwing dies intended for production of parallel pipe threads,
G series, in accordance with ISO 228-1.
The general dimensions of these dies (diameter, thickness and fixing dimensions) are in accordance
with ISO 2568 so as to permit the driving of hand-operated dies with the aid of the die stocks defined in
that document.

This International Standard specifies requirements for ISO metric screw threads for use with spectacle
frames. Provision is made for screw threads of the following nominal sizes: S0,8 × 0,2; M1,0 × 0,25;
M1,2 × 0,25; M1,4 × 0,3; M1,6 × 0,35 and M2,0 × 0,4 and for related taps and gauges.

ISO 11381:2016 specifies requirements for ISO metric screw threads for use with spectacle frames. Provision is made for screw threads of the following nominal sizes: S0,8 × 0,2; M1,0 × 0,25; M1,2 × 0,25; M1,4 × 0,3; M1,6 × 0,35 and M2,0 × 0,4 and for related taps and gauges.

ISO 2901:2016 specifies the basic and design profiles of ISO metric trapezoidal screw threads. ISO 2901:2016 is chiefly applicable to traversing threads for traversing motion on machines, tools, etc. It can also be used for fastening threads.

ISO 2903:2016 specifies a tolerance system for metric trapezoidal screw threads in accordance with ISO 2902. The tolerances refer to the design profile in accordance with ISO 2901. The tolerance system does not apply to trapezoidal screw threads with special requirements on axial displacement, for example, machine tool lead and feed screws and nuts.

ISO 2902:2016 specifies a series of diameter and pitch combinations for ISO metric trapezoidal screw threads having the basic and design profiles according to ISO 2901. ISO 2902:2016 is chiefly applicable to traversing threads for traversing motion on machines, tools, etc. It can also be used for fastening threads.

This International Standard specifies the characteristics of hexagon high nuts (style 2) with metric fine pitch thread, with nominal thread diameters, D, from 8 mm up to and including 36 mm, with product grade A for sizes D ≤ 16 mm and product grade B for sizes D > 16 mm. If, in special cases, specifications other than those listed in this International Standard are required, they can be selected from existing International Standards, for example ISO 724, ISO 898-2, ISO 965-1 and ISO 4759-1.

This part of ISO 898 specifies mechanical and physical properties of bolts, screws and studs made of carbon steel and alloy steel when tested at an ambient temperature range of 10 °C to 35 °C. Fasteners (the term used when bolts, screws and studs are considered all together) that conform to the requirements of this part of ISO 898 are evaluated at that ambient temperature range. They might not retain the specified mechanical and physical properties at elevated temperatures (see Annex B) and/or l...view more

ISO 27627:2014 specifies the technical delivery condition, manufacturing process, material requirements, configuration and dimensions, and verification and inspection procedures for aluminium alloy drill pipes manufactured in accordance with ISO 15546.
ISO 27627:2014 also specifies the gauging procedure for taper buttress thread (right and left) and adjoining tapered stabilizing shoulders (bores) made of aluminium alloy drill pipes and related steel tool joints.

This part of ISO 15245 specifies definitions, dimensions and tolerances of parallel screw threads of nominal diameter 30 mm (designated 30P), 25 mm (designated 25P) and 18 mm (designated 18P), for the connection of valves to medical and industrial gas cylinders. This part of ISO 15245 does not cover the connection requirements for:
- mechanical strength;
- gas tightness;
- capability of repeated assembly and dismounting operations.

ISO 965-1:2013 specifies a tolerance system for ISO general purpose metric screw threads (M) conforming to ISO 261. The tolerance system refers to the basic profile according to ISO 68-1.

2012-11-30 GVN: Draft for // vote received at ISO/CS (see notification in dataservice on 2012-11-29).