🔍 Key Concepts

• Use the chart’s bearing bore diameter (d in mm) curves and convert 5 1/2 inches to millimeters before choosing the correct curve. • At about 1000 rpm, move vertically on the x‑axis until you meet the curve for your calculated bore size, then read horizontally to the grease replenishment interval (hours) on the y‑axis. • Remember this chart is for radial ball bearings under normal load, so you don’t need to apply a load correction factor.

💭 Think About

• What is 5 1/2 inches in millimeters, and which d‑curve on the chart is closest to that value? • Once you are at 1000 rpm on the x‑axis and on the correct diameter curve, what approximate value do you read on the y‑axis, and which answer choice is closest to that value? • Does the interval you are reading make sense physically (larger bearings at the same speed usually need shorter grease intervals than smaller ones)?

✅ Before You Answer

• Double‑check your inch‑to‑millimeter conversion so you select the correct diameter curve. • Be sure you are reading from the radial ball bearing family of lines, not the cylindrical roller ones. • Verify that you are reading the hours scale correctly (it is logarithmic), and then pick the option nearest to your reading.