Opening their doors a few blocks away from Boeing headquarters, Renton Coil Spring has been a leading supplier to the aerospace industry since 1949. Since the early days, RCS has been a leader in aerospace innovation, including the development of Beta-C Titianium as a spring material, alongside Boeing and McDonald Douglas. Through its commitment to innovation and design, RCS has supplied springs to the leading aerospace companies in the world and continuously supplies to the highest echelon of aviation including Boeing Commercial Airplanes, Goodrich, Messier-Bugatti-Dowty, Honeywell, Textron Aviation and Woodard Governor.


RCS has in-depth design capabilities and is one of the few spring companies registered to ISO9001. This registration allows RCS to create their own drawings that reflect customer requirements. Their ability to optimize in the design process eliminates unnecessary rejections and allows problems to be caught prior to incurring additional drawing costs.

Source Control Drawings (SCD) and Test Capabilities

RCS excels and working to a source controlled drawing (SCD). RCS engineers are able to take the specifications from and SCD and produce a cost effective detailed solution. RCS is also available to fatigue test in house and has a full tooling department to produce any necessary modifications.

Material Technology

Renton Coil spring offers Titanium and other proprietary alloys that reduce weight and envelope. This weight and space savings is crucial to the aviation market.


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



Weight σƒ²/Gρ



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. 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.

Renton Coil Spring Co. is an ISO 9001:2008 registered firm and certified to AS9100. In addition, we are NADCAP certified to perform heat-treating of steel and titanium alloys.