d - 4 mm

D - 9 mm

B - 4 mm

d₁ - - 5.2 mm

D₂ - - 8.1 mm

r_1,2 - min. - 0.1 mm

d_a - min. - 4.6 mm

d_a - max. - 5.1 mm

D_a - max. - 8.4 mm

r_a - max. - 0.1 mm

Basic dynamic load rating - C - 0.54 kN

Basic static load rating - C₀ - 0.18 kN

Fatigue load limit - P_u - 0.07 kN

Reference speed - 140000 r/min

Limiting speed - 70000 r/min

Calculation factor - k_r - 0.015

Calculation factor - f₀ - 10

Mass bearing - 0.0013 kg

• Model Number: 638/4-2Z
• Inner Diameter：9mm Outer Diameter：4mm Width：4mm
• Type：Deep Groove Ball Bearings
• Update date：2025-12-12
• Application:hardware,Dental Drill etc,other processing,ventilation equipment,pump,Laser Cutting,machine tool spindle,printing machinery,container finishing,Doppler,raw material accessories
• Similar models:SKF W638/3-2Z SKF 638/4-2Z SKF W63804R-2Z FBJ 1638-2RS ISB SS638/3-ZZ SKF W63806-2RZ ISO 63800-2RS SKF W638-2RZ SKF W63804-2Z ISB 63803-ZZ
• BEARING POWER International Trading Co.,Ltd. specialize in 638/4-2Z products，there is large inventory of SKF 638/4-2Z . We has been built up long-term cooperation with SKF company, could make a bulk order of the 638/4-2Z Which SKF 638/4-2Z is the most authentic, must choose BEARING POWER, what a whole variety, reasonable price, guaranteed quality, prompt delivery via Global express.Any inquiry, never hesitate to E-mail or call +86-022-58519721 to contact us.

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