1、UDC 621.882.082.22 DEUTSCHE NORM December 1984 Thread run-outs and thread undercuts for pipe threads conforming to IS0 228 Part 1 m 76 Part 2 Gewindeauslufe, Gewindefreistiche fr Rohrgewinde nach IS0 228 Teil 1 Supersedes November 1953 edition. In keeping with current practice in standards published
2、 by the International Organization for Standardization flSO), a comma has been used throughout a? the decimal marker. Dimensions in mm 1 Scope and field of application This standard incorporates specifications for thread run-outs and thread undercuts for components with parallel pipe thread conformi
3、ng to IS0 228 Part 1. It applies to all standard parts, providing reference is made to this standard. In case of necessity, the letter symbols given here may be used. It is recommended that this standard also be adopted for non-standardized components with pipe thread as specified in IS0 228 Part 1.
4、 2 Dimensions, designation 2.1 External thread 2.1.1 Thread run-out xi normal x2 short 2.1.2 Distance from the last full form thread to the bearing face (for components threaded almost up to the head) 33L a2 a3 u a2 a3 2.1.3 Thread undercut Type A2 normal TypeB2 short Designation of a type 82 thread
5、 undercut: “1 Previously f and f2 respectively. Thread undercut DIN 76 - 82 w Continued on pages 2 and 3 Beuth Verlag GrnbH, Berlin 30, has exclusive sale rights for German Standards (DIN-Normen) DIN 76 Part 2 Engl. Price group ! Sales No. O105 01.86 Page 2 Table 1. DIN 76 Part 2 Size of thread Thre
6、ad Distance Thread undercut as in IS0 228 Part 1 0.907 1,337 1,814 2,309 min. inax. Pitch d max. 1 112B2A282 longs) hi3 normal4) short5) normal4)I short5) G 1/%A 2,3 1,3 3 2 4 d - 2 1,5 0,6 3.2 2,3 0,45 G114AtoG318A. 3,3 1,7 4 2,7 5,4 d - 2,5 2,5 1,1 47 3,3 0,7 6.3 43 0,9 G 112 Ato G 718A 45 2,3 53
7、3,6 7,2 d - 3 3,8 2 GlAtoG6A 5,a z,9 7 4,6 9,2 d - 4 4.6 2,3 8,l 5,8 1,2 The dimensions specified are approximately equal to 1 2p 1 4p I 1 33 P 1 2,5 P 1 03 P l) Dimensionsx, and u1 shall apply unless otherwise specified in the individual standards or indicated on the drawings *) Dimensions xp and a
8、2 shall apply only when a short thread run-out or a short distance is required for technical 3, Dimension u3 shall apply only for screws assigned to product grade C (previously, design 9). 4, The type A2 thread undercut shall apply unless otherwise specified in the individual standards or indicated
9、on the 5, The type 82 thread undercut shall apply only when a short thread undercut is required for technical reasons. reasons. drawings. 2.2 internal thread (blind tapped holes) 2.2.1 Thread run-out e, normal e2 short A 2.2.2 Thread undercut C2 normal D2 short 6 = useful thread length. Designation
10、of a type C2 blind tapped hole (thread undercut): Blind tapped hole DIN 76 - C2 *I Previously, f and fi respectively. 1) Recommended permissible deviation for the calculated dimension t: +y P. 2) da min. = 1 d; d, max. = 1 ,O5 d. 3) Special designs, e.g. 90“ or 60“ countersink, shall be indicated on
11、 the drawing. For nuts, the countersink diameters d, are specified in the individual product standards (dimensional standards). DIN 76 Part 2 Page 3 4,s 65 83 10 - Table 2. 3 d + 03 3,8 2,3 4 d + 0,5 5,3 3.3 5,5 d + 0,5 72 435 6,5 d + 0,5 9,2 5.8 - - 4P 2,5 P Size of thread as in IS0 228 Part 1 Pitc
12、h P “I“ 1,337 G 1 I4 to G 318 The dimensions specified are approximately equal IO BI i nd hol e ex tension Thread undercut gl e I I dg I min D2 normall) 1 short21 I Hi3 1 nozai3) 1 short4) g2 r I max. C2 1 D2 1 normal31 short41 Dimension el shall apply unless otherwise specified in the individual st
13、andards or indicated on the drawings. 2, Dimension e2 shall apply only for special designs where a short extension is required for technical reasons. 3, The type C2 thread undercut shall apply unless otherwise specified in the individual standards or indicated on the 4, The type D2 thread undercut s
14、hall apply only for special designs where a short thread undercut is required for drawings. technical reasons. Example of designation: Thread undercut DIN 76 - D2. DIN 76 Part 1 shall apply with regard to IS0 metric threads. DIN 76 Part 3 shall apply with regard to trapezoidal threads, buttress thre
15、ads and knuckle threads and other threads of coarse pitch. Standards referred to DIN 76 Part 1 DIN 76 Part 3 IS0 228 Part 1 Thread run-outs and thread undercuts for IS0 metric threads in accordance with DIN 13 Thread run-outs and thread undercuts for trapezoidal threads, buttress threads and knuckle
16、 threads and other threads of coarse pitch Pipe threads where pressure-tight joints are not made on the threads, designation, dimensions and tolerances Previous editions DIN 76 Part 2: 09.24,04.43, 11.53 Amendments The following amendments have been made in comparison with the November 1953 edition: a) The content of the standard has been completely revised and harmonized with IS0 228 Part 1 and DIN 76 Part 1. b) The specifications have been limited ta cover only pipe threads as DIN 11 on Whitworth threads has been withdrawn. International Patent Classification F 16 B 35-00
