BS ISO 20168:2016 pdf download

BS ISO 20168:2016 pdf download.Resistance welding — Locking tapers for electrode holders and electrode caps
1 Scope
This document specifies the dimensions and tolerances for electrode holders and of spot welding electrode caps, where a locking taper is used.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5182, Resistance welding — Materials for electrodes and ancillary equipment
ISO 5821, Resistance welding — Spot welding electrode caps
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 17677-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 locking taper
taper allowing for a tight fit between an electrode holder and the electrode cap as their taper angles differ by 0° 2ʹ 60ʺ, ensuring the electrode cap engagement point is at the skirt of the cap and electrode holder
Note 1 to entry: See Figure 1.
Note 2 to entry: Traditionally called “Fisher taper”.
Note 3 to entry: During welding, the electrode cap tightens further on the electrode holder.
4 Dimensions and tolerances
4.1 General
Table 1 gives the dimensions for three typically used electrode cap and holder sizes: 13 mm, 16 mm and 20 mm.
The taper angles of electrode caps and holders are to be verified by the use of certified ring gauges and plugs.
4.2 Electrode holders
The taper of the electrode holders shall be 2° 58ʹ 54ʺ in accordance with Figure 2.
4.3 Electrode caps
The taper of the electrode caps shall be 2° 56ʹ 53ʺ in accordance with Figure 2.
5 Designation
5.1 Electrode holders
Electrode holders shall be designated in accordance with this document and nominal diameter, d 1 .
EXAMPLE A spot welding electrode holder, with nominal diameter 20 mm is designated as follows:
ISO 20168:2016 – 20
5.2 Electrode caps
Electrode caps shall be designated in accordance with ISO 5821, except the number of this document shall be used to indicate that the cap has a locking taper.
EXAMPLE A spot welding electrode cap type B0, width d 1 = 16 mm, length l 1 = 20 mm, d 2 = 8 mm and a = 45°,is designated as follows:
ISO 20168:2016-B0 – 16 – 20 – 8 – 45
6 Material
The materials used shall be in accordance with ISO 5182.
7 Marking
The packaging shall be marked with the full designation and material used.