螺纹精度等级与尺寸公差

1、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 方君偉方君偉 .tw 2003/08/11 2 先學會計算三角形面積先學會計算三角形面積 30 3 計算六角形面積公式計算六角形面積公式 30 4 Nut thread 螺紋有效徑計算螺紋有效徑計算 Bolt thread 60o 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 H 1/8 H H Major Dia. Pitch

2、Dia. Minor Dia. 1/2 H 5 Basic thread profile - Metric Nut thread Basic Profile (Zero Line) Bolt thread 螺紋公差螺紋公差 Tolerance Nut Bolt 60o 6 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 Diameter M6 X 1.0 - 6g 之之 Pitch Diameter, Major Diameter Basic Pitch Dia. = D - 2 X 3/8H = D - 3/

3、4 X 0.866025P = D - 0.649519P = 6 - 0.649519 X 1.0 = 5.350 Basic Minor Dia. = D - 2 X 5/8H = D - 5/4 X 0.866025P = D - 1.083P = 6 - 1.083 X 1.0 = 4.917 Basic Pitch Dia. = D - 2 X 3/8H = D - 3/4 X 0.866025P = D - 0.649519P = 6 - 0.649519 X 1.0 = 5.350 g = - 26u 5.350 0.026 = 5.324 6級級 1.0 bolt PD tol

4、erance = 112u 5.324 0.112 = 5.212 g = - 26u 6.000 0.026 = 5.974 6級級 1.0 bolt MD tolerance = 180u 5.974 0.180 = 5.794 7 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 Diameter M6 X 0.75 - 6g 之之 Pitch Diameter, Major Diameter Basic Pitch Dia. = D - 2 X 3/8H = D - 3/4 X 0.866025P = D - 0

5、.649519P = 6 - 0.649519 X 0.75 = 5.513 Basic Pitch Dia. = D - 2 X 3/8H = D - 3/4 X 0.866025P = D - 0.649519P = 6 - 0.649519 X 0.75 = 5.513 g = - 22u 5.513 0.022 = 5.491 6級級 0.75 bolt PD tolerance = 100u 5.491 0.100 = 5.391 e = - 56u 6.000 0.056 = 5.944 6級級 0.75 bolt MD tolerance = 140u 5.944 0.140 =

6、 5.804 e = - 56u 5.513 0.056 = 5.457 6級級 0.75 bolt PD tolerance = 100u 5.457 0.100 = 5.357 g = - 22u 6.000 0.022 = 5.978 6級級 0.75 bolt MD tolerance = 140u 5.978 0.140 = 5.837 8 Thread tolerance position-Metric 5H 7H 6H Zero Line 基準線（零線）基準線（零線） 4h 6g 8g 電鍍餘隙電鍍餘隙 Allowance g f Nut thread Bolt thread e

7、 6e M6 X 0.75 -22 -38 -56 9 Technical data MaterialSteel General requirementsAs specified in DIN 267 Part1 ThreadTolerance6g StandardDIN 13 Parts 12 and 15 Mechanical properties Property class (material) 8.8,5.6,10.9 M39:subject to agreement StandardISO 898 Part 1 Limit deviations, geometrical toler

8、ances Product gradeA for products up to size M24 and L 10d or 150mm B for products exceeding size M24 or L 10d or 150mm StandardISO 4759 Part 1 10 Fasteners tolerances ISO4759 11 ISO tolerances 12 Tolerances h14h13 h13 +2P js15js14 Example: Size M6 X 25 13 Hexagon nuts weight calculation 六角螺帽重量六角螺帽重

9、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.2 14 DIN ISO 2768-1 Tolerance- Class (Line measurement) Limits in mm for nominal sizes in mm 0,5 to 3 above 3 to 6 above 6 to 30 above 30 to 120 above 120 to 400 above 400 to 1000 above 1000 to 2000 above 2000 to 4000 f (fine)

10、 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 2 c (coarse) 0,15 0,2 0,5 0,8 1,2 2 3 4 v (very coarse)- 0,5 1 1,5 2,5 4 6 8 Tolerance Class (radius and chamfer) Limits in mm for nominal sizes in mm 0,5 to 3 above 3 to 6 above 6 f (finne) 0,2 0,5 1 m (medium) c (coarse) 0,4 1

11、 2 v (very coarse) 15 DIN ISO 7168 Tolerance Class 0.5 to 3 Over 3 To 6 Over 6 To 30 Over 30 To 120 Over 120 To 400 Over 400 To 1000 Over 1000 To 2000 Over 2000 To 4000 F (fine) 0,05 0,05 0,1 0,15 0,2 0,3 0,5 0,8 M (means) 0,1 0,1 0,2 0,3 0,5 0,8 1,2 2,0 G (roughly) 0,15 0,2 0,5 0,8 1,2 2,0 3,0 4,0

12、Sg (very rough)- 0,5 1,0 1,5 2,0 3,0 4,0 6,0 16 表面粗度表面粗度 Surface roughness Roughness,RaGrade GradeWorking process umNumber Mark 6.3N9Sawing, Forging 3.2N8Shaping, Drilling, 1.6N7Broaching, Milling, Laser 0.8N6Electro-Chemical 0.4N5Turning, Grinding 0.2N4Electro-Polish, Honing 0.1N3Polishing 0.05N2Lapping 0.025N1Superfinishing 17 Wind turbi