Hudson Bearings From National Precision

NPB Stocks Hudson Ball Transfer and Ball Caster Products

Hudson Bearings is one of the oldest manufacturers of ball transfers in the United States and one of the most innovative. Hudson manufactures their broad and rapidly expanding product line in the USA. Their quality is unsurpassed and NPB is proud to inventory the Hudson product. Whether used in the traditional 'ball up' position for material handling or as a caster in the 'ball down' orientation for rolling applications such as retail store displays, Hudson is ready with the right product for your unique need. Contact us now for 10 pieces or 10,000, our technical sales team is ready to create a caster or transfer solution for you today.


Ball transfers solve a variety of material handling and motion control challenges, whether used in the traditional 'ball up' position or as a caster in the 'ball down' orientation. Ball transfers offer advantages to traditional casters, such as lower profiles and omnidirectional movement, often at a lower cost.

Common Applications

  • Air Cargo
  • Robotics
  • Store Fixtures
  • Laser & Plasma Cutters
  • Medical Devices
  • Shears
  • Military Logistics
  • Die Handling
  • Glass & Metal Manufacturing
  • Caster Substitution

Load Capacity

  • Equal load distribution over many ball transfers is seldom, if ever achieved. Load distribution is governed by the flatness, hardness, and smoothness of the load surface in contact with the balls, the ball transfer installation height variance, and system deflection.
  • To avoid exceeding the rated capacity of any individual ball transfer unit, sufficient ball transfers should be provided to afford a safety factor of 3. For example: the number of units (75 lb. maximum capacity) required to support a load of 750 lbs. would be 10 units x 3, or 30 units to obtain smooth rolling motion under varying degrees of flatness and ball contact. This applies to both 'ball up' and 'ball down' positioning.
  • In addition, the force required to put a load in motion is reduced as the number of ball transfer units under a load is increased, thereby reducing the coefficient of friction.
  • When calculating loads, the possibility of impact and unequal leveling should be considered. Self-leveling neoprene or rubber cushions placed under each unit can reduce these issues. We offer high-density neoprene cushions for several models of ball transfers, see the Hudson catalog for more information.


  • Arrangement of the ball transfer units depends on the weight of the load, surface of the application and undersurface of the conveyed load. Determine the number of units required to support the load based on the considerations stated above. Once the number of ball transfer units has been calculated, these units should be arranged symmetrically under the load. The minimum distance between ball transfers should be the length of the shortest dimension of the load divided by 2.5. This minimum spacing will support the conveyed article and prevent it from becoming unstable.
  • Our technical staff is available to assist you with mounting, loading, and spacing recommendations for your particular application.

Design & Materials

  • Minimum Grade 1000 carbon steel balls, higher than the competition. High grade main and support balls ensure rounder surfaces for smooth and consistent rolling.
  • Higher number of support balls to ensure load capacities are met.
  • In addition to the housing, support cups are zinc-plated to help retard rust and promote longer life of the ball transfer unit. All plating is RoHS compliant.
  • Unique dual-radius cup design: support cups are dimpled to encourage support ball fluctuation rather than simple rotation. The result is less support cup wear and longer life.
  • Foam seal helps wipe dirt particles away from main ball to promote easy rolling, as well as reduces contamination of support balls.
  • Stainless Steel balls are manufactured from Series 400 stainless steel.
  • Nylon main balls are machined, hardened, and non-marring.
  • All carbon steel units are sealed and lubricated to ensure maximum life, unless otherwise specified.
  • Many models are now available in all Stainless Steel (SS) for maximum corrosion resistance.
  • Additional types of main balls, including non-magnetic and hollow, are available on a custom order basis.


  • All products are made in the USA, in Hudson’s East Lyme, Connecticut facility.
  • Rigorous attention to detail and quality control ensures Hudson customers receive the finest products available. That is why they have been proud to stamp the Hudson name on all their ball transfers for over forty years.
  • CNC manufacturing capability ensures the highest tolerances, and allows us to manufacture custom products at production prices.

Part Numbering

Hudson Bearings part numbering details