Aerospace Springs

Safety, Efficiency, and stability. RCS provides the Aerospace Industry with what it needs to succeed.

Background
Renton Coil Spring started business just a few blocks away from Boeing in 1949. This gave RCS the ability to become a leading supplier to the Aerospace industry. In the 1980’s RCS developed Beta-C as a spring material in a joint venture with Boeing and Douglas. Through this important technological development, RCS was able to supply springs to a growing number of aerospace companies. Today, we supply high quality springs to a customer base that includes Boeing Commercial, Boeing Long Beach (C17), Goodrich, Messier-Dowty, Parker Hannifin and Woodward Governor.

RCS Quality Clauses D-6-1

Engineering
We have in-depth design capabilities and are one of the few spring companies registered to ISO 9001. Many spring companies claim that they are engineering experts yet are only registered to ISO 9002: RCS is fully compliant to ISO 9001 so we can create our own drawings reflecting your requirements. If you prefer to create your own drawings, we will willingly evaluate your drawing prior to release. It is quite usual for engineers to be unaware of spring industry drafting practices; this can cause multiple problems with unnecessary rejections and corresponding drawing revisions. Engineers that work with us regularly value the ability to submit drawings for pre-approval so that problems can be caught before the additional costs of releasing a drawing have been incurred.

Source Control Drawings (SCD) and Test Capabilities
RCS excels at working to an SCD. If you provide a source control drawing that specifies your most important requirements (loads, envelope, life, environment), we will submit our own drawing that will include the details necessary to produce a solution in the most cost effective way. If testing is required, we have in-house fatigue test equipment and a full tooling department to produce any necessary modifications.

Material Technology
We offer Titanium and other proprietary alloys that reduce weight and envelope that are particularly important for the aviation market.

 
  Beta-C Titanium 17-7 PH Stainless
Useable Stress (σƒ) ksi 100* (.689 GPa) 100* (1.72 GPa)
Shear Modulus (G)ksi 5600 (38.6 GPa) 11,000 (79.3 GPa)
Density (ρ) lbs/in³ .174 lbs/in³ (4.82 g/mm³) .282 lbs/in³ (7.982 g/mm³)
Volume σƒ²/G 1.78 .909
Weight σƒ²/Gρ 10.31 3.22
Relative Volume 0.50 (50%) 1.0 (100%)
Relative Weight 0.31 (31%) 1.0 (100%)

Assuming a material has an acceptable fracture toughness Kc (i.e. it is able to tolerate minor surface defects without fracturing), the three most important properties for a spring material are useable stress (σƒ), Shear Modulus (G) and density (ρ). In fact, two materials can be compared by evaluating the relative values of σƒ²/G if spring volume is of concern, or σƒ²/Gρ if spring weight is of concern. Results of a comparison between Beta-C and 17-7 can be seen in the table above. If we then invert the results and standardize using 17-7 as the baseline we can see that titanium requires approximately 50% of the space and will have 31% of the weight.