SKF RM30 Imperial Bearing 3-3/4" ID 12:1 Tapered Bore x 8-1/4" OD x 1-3/4"

SKF Self Aligning Ball Bearing 3-3/4" ID to 4" ID Nominal Tapered Bore (1:12) x 8-1/4" OD

The smaller side (3.750") is the nominal bore size.

The larger side (4.000") is the mouth of the taper.

This style is not meant to mount directly on a straight 4" shaft — it’s designed to mount on an adapter sleeve that matches your shaft size (commonly 3-1/4" or 3-1/2" shafts for RM30K).

Type: Self-aligning double row ball bearing tapered bore

Bore: 3.75" nominal (tapered 1:12, 4" at the mouth)

OD: 8.25" (≈ 209.55 mm)

Width: 1.75" (≈ 44.45 mm)

Country of manufacture: England

Weight: 16.9 lbs