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Frequently Asked Questions

What are aircraft pulleys?

Aircraft pulleys are a type of pulley designed to Military Specification MIL-DTL-7034 and the applicable Military Standards. Their qualified design assures that they will perform reliably in aircraft control system applications. Their grooves are generally designed to carry cables up to 1/4-inch outside diameter.

What makes aircraft pulleys unique to other pulleys?

Ralmark aircraft pulleys are made under rigid quality-controlled conditions from tested and qualified materials. Their design and construction assures they will meet rigid specification requirement.

What materials are used for aircraft pulleys?

Specifications require non-metallic aircraft pulleys to be made from reinforced phenolic resins that have been cured under heat, pressure and time into a uniform stable product.  Ralmark Company uses a specially engineered grade of laminated phenolic exceeding the specification material performance requirements.  Aluminum aircraft pulleys are manufactured from aircraft-grades of aluminum alloys.

What ball bearings are used?

Military Standard aircraft pulleys are mounted with ball bearings manufactured to rigid government and industry specifications and standards. The ball bearings used are a qualified product, made according to SAE-AS7949 and the applicable standards. Aircraft bearings, like aircraft pulleys, are Government (QPL) Qualified Products List items.

Are special aircraft pulley sizes and configurations available?

Yes, Ralmark will design special diameters and groove configurations to meet customer’s application requirements. Prototyping, engineering and testing and qualification services are also available as the application requires.

How are aircraft pulleys qualified?

Ralmark Company maintains a fully equipped physical-testing laboratory for the qualification of aircraft pulleys to MIL-DTL-7034. Qualified laboratories specializing in aircraft system testing perform environmental testing. Contact our customer service representative for further details.

Can aircraft pulleys be used for industrial or commercial applications?

Aircraft pulleys are widely used for industrial and commercial applications to guide cables, cords, wires, strands and filaments.  Some common industries are:  wire manufacturing cordage and textile, electro-mechanical devices, remote actuation of control devices, counter-balancing systems, theatrical and staging equipment, and medical equipment to name a few.

Can I have special pulleys made for my industrial and commercial application?

Yes!  Through our flexible machining processes, Ralmark Company applies proven manufacturing techniques using a variety of industrial plastics, ferrous and non-ferrous alloys. Sheave materials, protective finishes and bearings are selected to meet the requirements of the application.  We would be happy to review your application requirement for a proposal.

Are pulleys of this type more expensive?

Generally they are not. Ralmark Company is competitive with the industry for similar types and sizes of custom manufactured products of comparable quality. Customers gain a cost advantage through wide selection of standardized sizes. Contact our sales department for a competitive quote.

How do I contact Ralmark Company?

You can call, write, fax, e-mail, or use the convenient information request form.