Transit OEMS have multiple needs for seals: rail cars and buses need window seals, door seals, interior seals, exterior compartment seals, switch seals, route display seals, light fixture seals, and screen seals.  The list is endless.  Wiring protection in the form of grommet edging is used just as often.

City Bus

Through working with clients, DTi has found that transit OEMs need three core parameters for seals & wire protection: performance, safety, & reliability.

DTi's standard products meet these three parameters however increasingly clients come to us with specific application needs that require a custom product to meet those needs more precisely.

  • Custom Seal-Fast™ profiles
  • Custom Seal-Fast™ one-piece seals
  • Custom Spring-Fast® grommet edging


Standard products are steel-reinforced, silicone/EPDM seals with FST certifications


They are available in a wide range of profiles, materials, and compression loads however a custom seal can be tailored to the requirements and restrictions that your application needs, ensuring it offers the exact performance characteristics required.

DTi uses its in-house Collaborative Finite Element Analysis (CFEA) technology that evaluates the design for Compression Load Deflection (CLD) before production, reducing lead times and production costs.  Seals can ship in as little as 7-10 weeks.


One piece seal-black

One piece seal-black

One-piece seals perform better than seals with un-bonded terminal ends and offer many performance benefits.
Seal-Fast™ one-piece seals are made by bonding the ends of an EPDM/Silicone seal into a one-piece finished gasket.

These are the core benefits of one-piece seals:

  • Edges are sealed without terminating ends, providing complete 360⁰ protection
  • Higher efficiency: faster/easier to apply, no nonstandard operations like gluing or cutting
  • Can be designed to fit with a slight stretch so that it forms a tighter seal without deformation.
  • Lowers the Cost of Poor Quality (CoPQ) for manufacturers with lower failure rates vs. seals bonded onsite.
  • Minimize workplace health and safety concerns related to VOCs, glues, solvents or Hazmat.
  • At a $60 shop rate it lowers total install costs by 29.1%.
  • They also allow the potential for increased use of automation/robotics in the assembly process.

More details here – Why One-Piece Seals Make Sense for OEMs


Spring-Fast® grommet edging provides best-in-class wire protection without adhesive.  There are 11 variants in the range but sometimes clients need a custom design. Recently a major hot beverage machine OEM needed grommet edging that was high-heat resistant and had an extremely small profile. DTi created a custom profile.

Grommets thumb apply plate W1

All the base products can be customized to fit specific needs by modifying a range of design elements.

  • Size/Profile
  • Castle Geometry
  • Flexibility across axes
  • Polymer Coating
  • Added Sacrificial Cushion
  • TPE Encapsulation
  • Custom Pantone® colors

Its best-in-class performance comes from its spring steel castles that press into the edge to grip tightly without adhesive.


Standard products sometimes are not what OEMs need.

If you are an OEM looking to reduce costs, simplify and speed up production should consider DTi’s customized seals and grommets.

Contact us here to begin a conversation

Related post One Piece Seals Outperform Seals with Unbonded Terminating Ends.