How do you convert kilograms (kg) to Newtons (N)?

Strictly speaking, the two values describe different things: Kilogram is the unit for the mass of a body and Newton is the unit for a force.
Catalog specifications for the design of a bearing element are normally given as a force in Newtons (N). For aggregates, motors and equipment, the mass is typically given in kilograms (kg). A body with mass X kg generates a force due to the earth’s gravity. This force (N) corresponds to the mass (kg) multiplied by 9.81.

Example: A machine with a mass of 135 kg has 135 * 9.81 = 1324 N. For a quick estimate, the mass can be multiplied by 10 in a simplified way. In the example, this would be around 1350 N.