ISO 239 pdf download.Drill chuck tapers
1 Scope
This International Standard lays down the dimensions of drill chuck tapers and includes two distinct types :
a) Morse taper type;
b) Jacobs taper type.
It includes, for each type of taper, a table giving the dimensions.
2 Interchangeability
2.1 Morse taper type
See Figure 1 and Table 1 .
The tapered portions are identical with the following Morse tapers:
– No.1 , for tapers B6, B1 0 and B1 2;
– No.2, for tapers B1 6 and B1 8;
– No.3, for tapers B22 and B24.
The length of each of these tapers is, of course, distinctly less than the overall length of the corresponding Morse taper; each taper may be regarded as corresponding approximately either to that part of Morse taper nearest the small end (e.g. B1 0) or to the part nearest the large end (e.g. B1 2).
2.2 Jacobs taper type
See Figure 2 and Table 2.
Table 2 reproduces and classifies the normal dimensions of Jacobs tapers; they also observe the generally accepted designations, in spite of their somewhat illogical appearance.
The range of increasing values for diameter D contains two No. 2 tapers, the first of which is a short taper; between tapers Nos. 2 and 3, there are two interpolated tapers which bear the out-of-series numbers 33 and 6 respectively.
5 Designation
A drill chuck taper conforming to this International Standard shall be designated by:
a) “(drill chuck) Taper”;
b) reference to this International standard, i.e. ISO 239;
c) number of Morse taper, if designated as Morse taper type or capital letter J and number of Jacobs taper, if
designated as Jacobs taper type;
d) “s” in the case of short taper.
EXAMPLE 1
A drill chuck taper, Morse taper type, with Morse taper number B1 6 short is designated as follows:
Taper ISO 239 – B16s
EXAMPLE 2
A drill chuck taper, Morse taper type, with Morse taper number B1 6 is designated as follows:
Taper ISO 239 – B16
EXAMPLE 3
A drill chuck taper, Jacobs taper type, with Jacobs taper number 2 short is designated as follows:
Taper ISO 239 – J2s