JIS-B-1082-1987-R2003-ENG.pdf

udc 621.882.1 jis japan ese in dustrial stan dard stress area and bearing area for threaded fasteners jis b 1 0 8 2 - 1 9 8 7 o translated and published by japanese standards association o printed in japan 7s j i s b*ijo82 87 4933608 0009044 ij . translation without guarantee i n the event of any doubt arising, the original standard in japanese is to be evidence j i s b*lo82 87 m 4933608 0009045 3 m japanese industrial standard j i s stress area and bearing area for threaded fasteners b 1082-1987 1, scope screw thread(l) and the area of the part where a load due to the contact of the bearing surface of threaded fastener andthe other side is added, here- inafter referred to as the ?load area“. this japanese industrial standard specifies the stress area of metric furthermore, the method to obtain the stress area of unified thread is shown in reference. note (l) the stress area is used mainly for calculating the stress for the external thread, but is used for obtaining the proof load stress and the like of nut, too. applicable standards : jis b 0205-metric coarse screw threads jis b 0207-metric fine screw threads jis b 1001-diameter of bolt hole and counterborefor bolts and screws jis b 1002-dimensions of width across flats jis b 1021-tolerance system for threaded fasteners jis b 1051-mechanical properties of steels bolts and screws jis b 1101-slotted head machine screws jis b 1111-cross-recessed head machine screws jis b 1176-hexagon socket head cap screws jis b 1180-hexagon head bolts and hexagon head screws jis b 1181-hexagon nuts and hexagon thin nuts jis b 1182-square head bolts jis b 1186-sets of high strength hexagon bolt, hexagon nut and plain washers for friction grip joints jis b 1189-hexagon flange bolts jis 2 8401-rules for rounding off of numerical values reference standard: is0 898/1-mechanical properties of fasteners-part 1: bolts , screws and studs j i s b*l1082 87 = l1933b08 0009046 5 2 b 1082-1987 2. stress area 2.1 method to obtain stress area the stress area of metric screw thread shall be obtained according to the following formula (1) or (2). provided that the obtained numerical value shall be rounded in three significant figures in accordance with jis z 8401 unless special reasons exist. (1) as= zc ( 7 ) d+d3 * . where a, : stress area of metric screw thread (mm2) d : basic size of major diameter of external thread (mm) d, : basic size of pitch diameter of external thread (mm) 4 : value obtained by reducing 1/6 of the height of fundamental triangle h from the basic size of minor diameter of external thread ( 4 ) h : height of fundamental triangle (h = 0.866 025 p) (mm) p : pitch of screw thread (mm) zc : ratio of the circumference to its diameter. z = 3.1416 is used for the formula (2). remarks 1. the formula (1) has been specified in jis b 1051 and coincides with the specification of is0 898/1. the formula (2) is obtained by inducing a, = f ( d - h ) from the formula (1) and putting n = 3.1416 and h = 0.866025 p into (2). 13 2. 2.2 stress area corresponding to nominal designation of metric screw thread the stress areas of the nominal designation of screw threads ofm to m 68 specified in jis b 0205 and the stress areas corresponding to fine screw threads of nominal designation of screw threads of m 8 .x 1 to m 39 x 3 and nominal designation of screw threads of m 72 x 6 to m 130 x 6, which are specified in table 3 of jis b 0207, are shown in table 1. 1 -,-,- j i s b*l082 87 w 4933608 0009047 7 * 3 b 1082-1987 table 1 unit: mm2 metric coarse screw thread metric fine screw thread stress area nominal des- stress area (a,) ignation of (a,) screw thread nominal des- ignation of screw thread m 1 m 1.1 m 1.2 pitch (mm) 0.25 0.25 0.25 - 0.460 0.588 1 i 180xi.25 1 0.732 m 12x1.25 39.2 61.2 92.1 m 1.4 m 1.6 *m 1.7 0.3 0.35 0.35 0.983 m 14x1.5 1.27 m 16x1.5 1.48 1 m 18x1.5 i 125 167 216 m 1.8 m 2 m 2.2 0.35 0.4 0.45 1.70 m 20x1.5 2.07 m 22x1.5 2.48 i m 24x2 1 272 333 384 0.4 0.45 0.45 2.91 m 27x2 3.39 i m 30x2 i 3.73 m 33x2 496 621 761 *m 2.3 m 2.5 *m 2.6 h i 3 m 3.5 m 4 m 4.5 m 5 m 6 5.03 m 36x3 865 6.78 1030 8.78 0.5 0.6 0.7 0.75 0.8 1 1 1.25 1.25 m 7 m 8 m 9 m 10 m 11 m 12 1.5 1.5 1.75 m 14 m 16 m 18 2 2 2.5 m 20 m 22 m 24 2.5 2.5 3 245 303 353 m 27 m 30 m 33 3 3.5 3.5 459 561 694 m 36 m 39 m 42 4 4 4.5 817 976 1120 4.5 5 5 1310 1 470 1760 m45 m48 m 52 m 56 m60 m64 m68 5.5 5.5 6 6 - 2 030 2 360 2 680 3 o60 remarks 1 . “he nominal designation of screw thread appended with *mark is expected to be abolished in the future. the value corresponding to the metric fine screw thread of nominal designa- tion of screw thread of m 72 x 6 to m 130 x 6 applies to the metric coarse screw thread of more than m 68 mainly. and the nominal designation up to m 130 x 6 is used for jis b 1181. 2. furthermore, the nominal designation to m 80 x 6 is used for jis b 1180 -,-,- j i s b*(1082 87 m 4933608 0009048 9 4 b 1082-1987 3. load area 3.1 method to obtain load area the load area of threaded fasteners shall be obtained in accordance with the formulae of table 2 where the form of the bearing surface contacting to the opposite surface is circular, hexagonal.and square though that load area varies according to the form and dimensions of bearing surface, the size of bore diameter of bolt, the presence of washer and the like. rounded off to three significant figures in accordance with jis z 8401 unless special reasons exist. provided that the obtained value shall be table 2 form of bearing surface i formula of load area circular hexagonal square where abi : load area in the case of circular bearing surface (mm2) a,: load area in the case of hexagonal bearing surface (mm2) ab3 : load area in the case of square bearing surface (mm2) du,: diameter(2) of bearing surface (mm) s : width across flats(3) of hexagon and square (mm) dh : bore diameter(4) of bolt (mm) i t : ratio of the circumference to its diameter. n = 3.1416 is used in the formula of table 2. notes (2) where there is roundness or chamfer on the outer circumfer- ence, take the diameter of the plane part excepting it (see figs. 1 to 4). the form of washer faced bearing surface and chamfered bearing surface shall be regarded as circle (see fig. 3 and fig, 4). take the diameter of chamfered part as d h when the bolt hole has been chamfered (see fig. 5). ( 3 ) (4) -,-,- jis b*lto82 87 4933b08 0009049 o = 5 b 1082-1987 fig. 1 fig. 2 fig. 3 fig. 4 fig. 5 3.2 load area corresponding to nominal designation of screw thread of threaded fasteners and ratio of area the load area ( a,) for each nominal designation of screw thread when combining the threaded fasteners shown in table 3 and bolt holes and the ratio corresponding to the stress area (a,) of table 1 ( &/a, : hereinafter referred to as the ifratio of areatf) are shown in table 4 and table 5. table 3 threaded fasteners division by the class size of width . across flats ordinary type i large type hexagon socket square head ordinary type boit (5) flanged hexagon head bolt (7) i- i pan headed l- machine screw ( 8 ) presence of washer faced head or nut range of nomi- nal diameter of screw thread mm i without 3 to 80 with 1 3 t o 39 (washer faced) without with (washer faced) with (washer faced) without 8 to 39 12 to 39 without 3 to 58 without 3 to 24 i without 1 4 to 16 i i 2 t o without i diameter of bolt hole mm in accordance with grade 2 of diameter of bolt hole of jis b 1001 load area and ratio of area in accord- ance with table 4. in accord- ance with table 5. notes (5) the ordinary type and small type of hexagon bolt are in accordance with jis b 1180 and the large type (washer faced) is i n accordance with jis b 1186, and the square head bolt is in accordance with jis b 1182. provided that the ordinary type, small type and large type of by the size of width across flats“ shall be in accordance with ordinary type series, small type series and large type series of the %idth across flats of hexagon“ specified in attached table 2 of jis b 1002. the hexagon socket head cap screw shall be in accordance with jis b 1176. the flanged hexagon head bolt shall be in accordance with jis b 1189. the pan head machine screw shall be in accordance with jis b 1101 and jis b 1111. where the form and dimensions of the bearing surface relating to the nominal designation of screw thread of nut is the same as those of hexagon head bolt, square head bolt and flanged hexagon head bolt of table 3, it should be preferable to apply the load areas of table 4 and table 5 to that nut, too, (6) (7) ( 8 ) remark: -,-,- j i s b*lotiz ti7 4933608 0009050 7 w ii i n e e ii ii ii ii ii ii ii ii ii ii ii ii 2 5 2 5 ? ? nn t - t - i! d u : e a n n c, 4 o u m al c c o bc m x 9) g u o m n $ iw o o h u e p c m m $ p m s y( u . * x a i n 3 - 3 2 qg e a 5 e 2 p 2 e j i s b*lo82 87 4933608 oooocil 9 7 n x - s i- n 5: y - l-4 cr? m. i- o 3 - x o 2 s - i - b 1082-1987 & m a l o u m & n n r) w 8 b 2082-1987 j i s b*1082 87 w 4933b08 0009053 2 e q co =i g m v) e .rl p al sl o w g p 3 e sl c 4 e v a 5 m *i al 0 w & o o u a fi sl v) sl u rl o p p m al e 3 g p & j 9 d 2 z i -0 u w al w o n v w u k m e d & m w p w o ! i l u i a sl w n w .-i v m - c-: e? 3 o d 2 p ml o w o al n sl v) o sl v) m p al e (il sl al rl o c ci rl o p w o n .d v 2 2 c-: u) co o 3 u) 2 ? 5 o n si ri m 2 - ln 2 x 2 e 2 - 2 x 2 e 4 p w 2 e 2 i4 x i - m m e n m .-i u 2 e 2 e m e j i s bm1082 87 m 4933608 0009054 4 m 9. b 1082-1987 reference method to obtain stress area of unified thread the stress area of unified thread shall be obtained according to the following formula. rounded off to three significant figures in accordance with jis z 8401 unless special reasons exist. provided that the obtained numerical value shall be a,=0.785 4 ( d- x 25.4)2 n where a,: stress area of unified thread (mm2) d : basic size of major diameter of external thread mm) n : number of thread ridges per 25.4 mm remarks 1. the formula in this reference shall