1、UDC 621.951.43 DEUTSCHE NORM April 1986 I I 60 centre drills Types R, A, and B DIN 333 Zentrierbohrer mo; Form R, A und B Supersedes November 1973 edition. In keeping with current practice in standards published by the International Organization for standardization (ISO), a comma has been used throu
2、ghout as the decimal marker. See Explanatory notes for connection with International Standards IS0 866- 1975, IS0 2540 - 1973, and IS0 2541 - 1972, published by the International Organization for Standardization (ISO). Dimensions in mm 1 Scope and field of application Centre drills dealt with in thi
3、s standard are used for making 60 centre holes as specified in DIN 332 Part 1, of type R, of type A for sizes up to and including 12,5 mm X 26,5 mm and of type 6 for sizes up to and including 10mrn X 21,2 mm. Type A and B centre drills can also be used for making the centring portion of type C centr
4、e holes as specified in DIN 332 Part 1, since the centring portion is the same for types A, B and C centre holes. 2 Dimensions, designation Centre drills are not expected to conform to the designs illustrated here; compliance is only required in the case of the dimensions specified. 2.1 Type R R0,5
5、x 3,15 and R0,8 X 3,15 centre drills R1 x 3,15 to R12,5 X 31,5 centre drills w I Other dimensions as in figure 1. Figure 1. Figure 2. Centre drill DIN 333 - R 4 X 10 Designation of a 60 centre drill, type R, with dl = 4mm and d2 = 10mm: Table 1. Continued on pages 2 to 4 DIN 333 Engl. Price group 6
6、rth Verlag GrnbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). Sales No. 0106 04.87 Page 2 DIN 333 di d2 Il 2) Limit Limit deviations deviations 1) h9 e 0,s 3,15 25 O 0,8 3,15 25 e1 3,15 31,5 + 0.14 3,15 31,5 e i,25 0 1,6 4 35,5 e2 5 40 e 25 63 45 O *2 2.2 Type A A0,5 x
7、 3,15 and A0,8 X 3,15 centre drills 12 2) Limit deviations + 0,2 OB 0 1,1 0 + 0,4 + 0.6 0 13 1,6 2 2,5 t 0.8 0 Al x 3,15 to A12,5 x 31,5 centre drills I- Other dimensions and details as in figure 3 Figure 3. Figure 4. Designation of a 60“ centre drill, type A, with dl = 4mm and d2 = 10mm: Centre dri
8、ll DIN 333 -A 4 X 10 Table 2. DIN333 Page 3 2.3 Type B Figure 5 Designation of a 60 centre drill, type B, with d, = 4mm and d2 = 14mm: Centre drill DIN 333- 84 X 14 Table 3 Material High speed steel at the manufacturers discretion or subject to agreement. Finish Right-hand cutting. Straight or spira
9、l-fluted at the manufacturers discretion. Left-hand cutting centre drills may be ordered according to this standard. In such cases, the designation shall then read, for instance for a type R centre drill with dl = 4mm and d2 = lOmm, left-hand cutting (L): Centre drill DIN 333 - R 4 X 1 O L Limit dev
10、iations of the 60 included angle made by type A and type B centre drills: -7 Marking Centre drills conforming to this standard shall be marked with symbol R, A or B, diameters dl and dp, the material and the manufacturers name or symbol. I Page4 DIN333 I Standards referred to DIN 332 Part 1 60 centr
11、e holes; types R, A, 6, and C IS0 866-1975*) Centre drills for centre holes without protecting chamfers; type A IS0 2540-1973) Centre drills for centre holes with protecting chamfers; type B IS0 2541 -1972*) Centre drills for centre holes with radius form; type R Previous editions DIN 320: 10.23, 07
12、.59. 01.62; DIN 321: 10.23; DIN 333: 09.22, 03.24, 04.25, 03.43, 07.59, 01.62,11.73. Amendments The following amendments have been made in comparison with the November 1973 edition. a) The length of type R and type A 0,5 x 3,15 and 0,8 x 3,151 centre drills, l, has been changed to 25mm. b) The desig
13、nation has been harmonized with DIN 820 Part 27. c) The standard has been editorially revised. Explanatory notes Some dimensions of centre drills as specified in this standard agree with those specified in IS0 866, IS0 2540 and IS0 2541. In addition to the centre drills specified in IS0 866 and IS0
14、2541, type A 12,5 X 31,5, R 0,5 X 3,15,0,8 X 3,15 and 12,5 X 31,5 centre drills have been included. As a departure from the above IS0 Standards, DIN 333 provides for an X between diameters dl and d2 in the designation, whereas, according to the IS0 Standards, an oblique stroke is to be used (e.g. DI
15、N: 4 X 10 and ISO: 4/10). Since the designation of the centre hole includes the major diameter, and the designation of the centre drill the shank diameter, the designations of a centre hole and of the corresponding tool are not identical except for diameter di. A DIN 332-A4 X 8,5 centre hole is thus
16、 to be made with a DIN 333-A4 X 10 centre drill, for example. The values of 2, and Z2 specified relate to new centre drills prior to re-sharpening which is allowed for by the minimum values of centre hole epth, t, specified in DIN 332 Part 1. International Patent Classification 0 23 B 49/04 *) English-language and French-language versions of IS0 Standards are obtainable from Beuth Verlag GrnbH, Burggrafen- straBe 6. 0-1000 Berlin 30.
