螺纹精度等级与尺寸公差

1、screw threads and tolerances 扣件之螺紋精度等級與尺寸公差扣件之螺紋精度等級與尺寸公差(複習與演算複習與演算)by: steven fang .tw2003/08/11 先學會計算三角形面積先學會計算三角形面積30計算六角形面積公式計算六角形面積公式30 nut thread螺紋有效徑計算螺紋有效徑計算 bolt thread60o螺距螺距 p有效徑有效徑陽螺紋大徑陽螺紋大徑(螺絲外徑螺絲外徑)陰螺紋小徑陰螺紋小徑( (螺帽孔徑螺帽孔徑) )1/4 h1/8 h hmajor dia.pitch dia.minor dia.1/2 hbasic thread pro

2、file - metricnut threadbasic profile (zero line) bolt thread螺紋公差螺紋公差tolerancenutbolt60o學會計算基本螺紋尺寸學會計算基本螺紋尺寸(i)m6 x 1.0 - 6h basic pitch diameter, minor diameterm6 x 1.0 - 6g 之之 pitch diameter, major diameterbasic pitch dia. = d - 2 x 3/8h = d - 3/4 x 0.866025p = d - 0.649519p = 6 - 0.649519 x 1.0 =

3、5.350basic minor dia. = d - 2 x 5/8h = d - 5/4 x 0.866025p = d - 1.083p = 6 - 1.083 x 1.0 = 4.917basic pitch dia. = d - 2 x 3/8h = d - 3/4 x 0.866025p = d - 0.649519p = 6 - 0.649519 x 1.0 = 5.350g = - 26u 5.350 0.026 = 5.3246級級 1.0 bolt pd tolerance = 112u 5.324 0.112 = 5.212g = - 26u 6.000 0.026 =

4、5.9746級級 1.0 bolt md tolerance = 180u 5.974 0.180 = 5.794學會計算基本螺紋尺寸學會計算基本螺紋尺寸(ii)m6 x 0.75 6e之之 pitch diameter, major diameterm6 x 0.75 - 6g 之之 pitch diameter, major diameterbasic pitch dia. = d - 2 x 3/8h = d - 3/4 x 0.866025p = d - 0.649519p = 6 - 0.649519 x 0.75 = 5.513basic pitch dia. = d - 2 x

5、3/8h = d - 3/4 x 0.866025p = d - 0.649519p = 6 - 0.649519 x 0.75 = 5.513g = - 22u 5.513 0.022 = 5.4916級級 0.75 bolt pd tolerance = 100u 5.491 0.100 = 5.391e = - 56u 6.000 0.056 = 5.9446級級 0.75 bolt md tolerance = 140u 5.944 0.140 = 5.804e = - 56u 5.513 0.056 = 5.4576級級 0.75 bolt pd tolerance = 100u 5

6、.457 0.100 = 5.357g = - 22u 6.000 0.022 = 5.9786級級 0.75 bolt md tolerance = 140u 5.978 0.140 = 5.837thread tolerance position-metric5h7h6hzero line 基準線（零線）基準線（零線）4h6g8g電鍍餘隙電鍍餘隙 allowancegfnut threadbolt threade6em6 x 0.75-22-38-56technical datamaterialsteelgeneral requirementsas specified in din 267

7、 part1threadtolerance6gstandarddin 13 parts 12 and 15mechanicalpropertiesproperty class(material)8.8,5.6,10.9 m39:subject to agreementstandardiso 898 part 1limitdeviations,geometricaltolerancesproduct gradea for products up to size m24and l 10d or 150mmb for products exceeding sizem24 or l 10d or 15

8、0mmstandardiso 4759 part 1 fasteners tolerances iso4759 iso tolerancestolerancesh14h13h13+2pjs15js14example: size m6 x 25hexagon nuts weight calculation六角螺帽重量六角螺帽重量 g/pc= (六角面積六角面積 - 圓面積圓面積) x 厚度厚度 x 7.85g/1,000圓面積圓面積 = /4 x pitch dia.2din iso 2768-1tolerance- class(line measurement)limits in mm for

9、 nominal sizes in mm0,5to3above3 to 6above6to30above30to120above120to400above400to1000above1000to2000above2000to4000f (fine) 0,05 0,05 0,1 0,15 0,2 0,3 0,5-m (medium) 0,1 0,1 0,2 0,3 0,5 0,8 1,2 2c (coarse) 0,15 0,2 0,5 0,8 1,2 2 3 4v (very coarse)- 0,5 1 1,5 2,5 4 6 8toleranceclass(radius and chamf

10、er) limits in mm for nominal sizes in mm0,5to3above3to6above6f (finne) 0,2 0,5 1m (medium)c (coarse) 0,4 1 2v (very coarse)din iso 7168tolerance class0.5to3over3to6over6to30over 30to120over120to400over400to1000over1000to2000over2000to4000f (fine) 0,05 0,05 0,1 0,15 0,2 0,3 0,5 0,8m (means) 0,1 0,1 0

11、,2 0,3 0,5 0,8 1,2 2,0g (roughly) 0,15 0,2 0,5 0,8 1,2 2,0 3,0 4,0sg (very rough)- 0,5 1,0 1,5 2,0 3,0 4,0 6,0表面粗度表面粗度 surface roughnessroughness,ragrade gradeworking processumnumber mark6.3n9sawing, forging3.2n8shaping, drilling,1.6n7broaching, milling, laser0.8n6electro-chemical0.4n5turning, grinding0.2n4electro-polish, honing0.1n3polishing0.05n2lapping0.025n1su