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H7/p6 fit: locational interference (press) fit

Parts pressed together that must not move: bushings pressed into housings, dowel pins in steel, gears pressed on shafts without keys.

Nominal size (mm)Hole H7 (µm)Shaft p6 (µm)Max. clearance (µm)Min. clearance (µm)
1–3+10 / 0+12 / +6+4-12
>3–6+12 / 0+20 / +120-20
>6–10+15 / 0+24 / +150-24
>10–18+18 / 0+29 / +180-29
>18–30+21 / 0+35 / +22-1-35
>30–50+25 / 0+42 / +26-1-42
>50–80+30 / 0+51 / +32-2-51
>80–120+35 / 0+59 / +37-2-59

Negative clearance means interference. Example: a Ø20 H7/p6 fit has a hole of 20.000–20.021 mm and a shaft of 20.022–20.035 mm.

On the drawing

Write the fit after the size: Ø20 H7 on the hole and Ø20 p6 on the shaft. Shops ream H7 holes routinely; tight shaft grades usually need fine turning or grinding.

Draw your own part

Drop a STEP file into DrawMyPart. It finds every body, asks you to confirm threads, fits and tolerances, and draws a sheet your manufacturer can build from.

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