機(jī)械制圖公差尺寸及查表

1、公差表在國(guó)家標(biāo)準(zhǔn)中，公差與配合方面有“標(biāo)準(zhǔn)公差數(shù)值表”、“軸的基本偏差數(shù)值表”和“孔的基本偏差數(shù)值表”等三張最常用的表格，所有孔、軸的上、下偏差均是根據(jù)這三張表格計(jì)算得出的。這三張表格不僅適用于光滑圓柱配合，也包括其他表面或結(jié)構(gòu)的尺寸公差，以及由它們組成的配合。對(duì)圓柱（孔表面或軸表面）它是指直徑，對(duì)鍵寬與鍵槽寬指的是寬度，這時(shí)鍵寬相當(dāng)于軸，鍵槽寬相當(dāng)于孔。公差表中''基本尺寸”一欄的大于3至6,大于6至10……是尺寸分段，單位為mm,凡是屬于這一段范圍的尺寸，都可以查偏差數(shù)值。公差表中的偏差數(shù)值是以rm（微米）為單位的，但在圖樣中標(biāo)注偏差數(shù)值時(shí)，則以mm（毫米）為單位。根據(jù)國(guó)際標(biāo)準(zhǔn)，以下為基本尺寸0-500mm，4-18級(jí)精度標(biāo)準(zhǔn)公差表?；境叽绻钪礗T4IT5IT6IT7IT8IT9IT10IT11IT12IT13IT14IT15IT16IT17IT18大于到pmmm334610142540600.100.140.250.400.601.01.43645812183048750.120.180.300.480.751.21.861046915223658900.150.220.360.580.901.52.210185811182743701100.180.270.430.701.101.82.718306913213352841300.210.330.520.841.302.13.33050711162539621001600.250.390.621.001.602.53.95080813193046741201900.300.460.741.201.903.04.6801201015223554871402200.350.540.871.402.203.55.412018012182540631001602500.400.631.001.602.504.06.318025014202946721151852900.460.721.151.852.904.67.225031516233252811302103200.520.811.302.103.205.28.131540018253657891402303600.570.891.402.303.605.78.940050020274063971552504000.630.971.552.504.006.39.7注：基本尺寸小于1mm時(shí)，無(wú)IT14至IT18。（end）2、查表方法以下為公差表的查表方法。舉例：①230H8/t9,這是表示標(biāo)準(zhǔn)公差為8級(jí)的基準(zhǔn)孔H8與基本偏差代號(hào)為t的9級(jí)的軸t9組成的過(guò)盈配合。對(duì)孔，先從標(biāo)準(zhǔn)公差數(shù)值表中查出IT8：對(duì)應(yīng)于基本尺寸分段＞180?230的IT8為72rm。再查孔的基本偏差表：對(duì)應(yīng)于尺寸分段＞180?230的H的基本偏差（下偏差）為零。同樣，再?gòu)臉?biāo)準(zhǔn)公差表和軸的基本偏差表中查得：IT7=46rm,t的下偏差為+196rm?？椎幕酒顢?shù)值（GB/T1800.3-1998）基本偏差數(shù)值

基本尺寸mm下偏差EI上偏差ES所有標(biāo)準(zhǔn)公差等級(jí)IT6IT7IT8<IT8>IT8<IT8>IT8<IT8>IT8<IT7大于至ABCCDDEEFFFGGHJSJKMNP至ZC3+270+140+60+34+20+14+10+6+4+20由公式計(jì)算+2+4+600-2-2-4-4在大于IT7的相應(yīng)數(shù)值上增加-個(gè)△值36+270+140+70+46+30+20+14+10+6+40+5+6+101+△4+△-48+△0610+280+150+80+56+40+25+18+13+8+50+5+8+121+△6+△-610+△01014+290+150+95+50+32+16+60+6+10+151+△7+△-712+△014181824_lqn+160+110+65+40+20+70+8+12+202+△8+△-815+△024301—3003040+310+170+120+80+50+25+90+10+14+242+△9+△-917+△04050+320+180+1305065+340+190+140+100+60+30+100+13+18+282+△11+△1120+△06580+360+200+15080100+380+220+170+120+72+36+120+16+22+343+△13+△1323+△0100120+410+240+180120140+460+260+200+145+85+43+140+18+26+413+△15+△1527+△0140160+520+280+210160180+580+310+230

180200+660+340+240+170+100+50+150+22+30+474+△17+△1731+△0200225+740+380+260225250+820+420+2802528+92+4+30008000+190+110+56+17+25+36+55280315+1050+540+33004+△20+△2034+△03135+12+6+355000060+2+1+6+10+2+3+64+△21+△37+△0355400+1350+680+400102528990214045+15+7+400006040+2+1+6+20+3+4+65+△23+△40+△0450500+1650+840+48030358033623500630+260+145+76+2200-26-44630800+290+160+80+2400-30-508001000+320+170+86+2600-34-5610001250+350+195+98+2800-40-6612501600+390+220+110+3000-48-7816002000+430+240+120+3200-58-9220002500+480+260+130+3400-68-11025003150+520+290+145+3800-76-135注：1、基本尺寸小于或等于1mm時(shí)，基本偏差A(yù)和B及大于IT8的N均不采用。2、js的偏差=，其中ITn是IT值數(shù)；公差帶JS7至JS11,若ITn值數(shù)是奇數(shù)，則取偏差=。3、對(duì)小于或等于IT8的K、M、N和小于或等于IT7的P至ZC,所需△值從表內(nèi)右側(cè)選取。例如：18?30mm段的K7：△=8呼，所以ES=-2+8=+6pm,18?30mm段的S6：△=4口］m,所以ES=-35+4=-31pm

4、特殊情況：250?315mm段的M6,ES=-9pm（代替-11pm）。軸的基本偏差數(shù)值（摘自GB/T1800.3—1998）（mm）基本偏差數(shù)值上偏差es下偏差ei基本尺寸/mm所有標(biāo)準(zhǔn)級(jí)公差等IT5和IIT7IT8IT4至I<IT3〉IT所有標(biāo)準(zhǔn)公差等級(jí)TT767大于至aBcCddeefffgghjsJKMnPRSTUvXYZzaZbzc32701406034201410642024600+2+4+6+10+14+18+20+26+32+40+603627014070463020141064024+10+4+8+12+15+19+23+28+35+42+50+8061028015080564025181385025+10+6+10+15+19+23+28+34+42+52+67+9711+4+5+6+9+10421955032160+0++1+1+228+300403014189050636172833+39+45+60+77+108+15012+4+4+5+6+7+9+1+1843116540200+0++1+2+2+317433836882430006010748285285+41+48+55+64+75+88+118+160+21834311+4+6+6+8+9+1+1+2+20010702080502590510+20+9+17+26+34+43808041248007445+5+7+8+9+1+1+1+2+30031140171436804225

20803056311+4+5+6+8+1+1+1+1+2+3+405494+111367022244722600050001603010012+0+2+368321007202+4+5+7+1+1+1+1+2+2+3+4506053950220467410746080000801003802201701723612015+0+13+2+3+51+71+91+124+146+178+214+258+335+445+585100120410240180209337+54+79+104+144+172+210+254+310+400+525+690120140460260200+63+92+122+170+202+248+300+365+470+620+80014016052028021014585431401118+30+15+27+43+65+100+134+190+228+280+340+415+535+700+900160180580310230+68+108+146+210+252+310+380+465+600+780+1000180200660340240+77+122+166+236+284+350+425+520+670+880+1150200225740380260170100501501321+40+17+31+50+80+130+180+258+310+385+470+575+740+960+1250225250820420280+84+140+196+284+340+425+520+640+820+1050+1350

250280920480300190110+4++34+56+94+158+218+315+385+475+580+710+920+1200+15502803151050540330561701626020+98+170+240+350+425+525+650+790+1000+1300+1700315355120060036021621801828+0+21+3+6+108+190+268+390+475+590+730+900+1150+1500+190035540013506804001025472+114+208+294+435+530+660+820+1000+1300+1650+2100400450150076044021682002032+0+23+4+6+126+232+330+490+595+740+920+1100+1450+1850+240045050016508404803035508+132+252+360+540+660+820+1000+1250+1600+2100+2600500560217622000+26+4+7+150+280+400+600560630604548+155+310+450+660630710218024000+30+5+8+175+340+500+740710800906008+185+380+560+840

8900++5601+210+430+620+94091660003+220+470+680+51131；；000+6+1+2