Blast® 168 Natural Rubber
Atlas Bearing™ 168 is a 60 Shore A Natural Rubber bearing pad designed to evenly transfer load from beams to supports in bridge bearing and structural applications. It delivers 2250 min. psi tensile strength and 400% min. elongation with a compression set of 25% max. (22 hours @ 158°F) — the lowest compression set of any Atlas Bearing™ grade. The material meets AASHTO M251-06 and AASHTO LRFD bridge construction specification Section 18.2, and is rated to -40°F cold temperature per ASTM D2137.
Key Properties
- Durometer / Hardness (Shore A): 60 — ASTM D2240
- Tensile Strength: 2250 min. psi — ASTM D412
- Elongation: 400% min. — ASTM D412
- Compression Set, 22 Hours @ 158°F: 25% max. — ASTM D395B
- Specific Gravity: 1.13 g/cc — —
- Cold Temperature: -40°F — ASTM D2137
We want to help!
Enter your information and we'll get you in touch with our knowledgable staff. We know how important to the right product for your project.
Request a Consultation
- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Material / Substrate | Natural Rubber | — |
| Color | Black | — |
| Specific Gravity | 1.13 g/cc | — |
| Thickness | 1/2″, 5/8″, 3/4″, 1″ | — |
Mechanical Properties
| Property | Value | Test Method |
| Durometer / Hardness (Shore A) | 60 | ASTM D2240 |
| Tensile Strength | 2250 min. psi | ASTM D412 |
| Elongation | 400% min. | ASTM D412 |
| Compression Set, 22 Hours @ 158°F | 25% max. | ASTM D395B |
Thermal Properties
| Property | Value | Test Method |
| Cold Temperature | -40°F | ASTM D2137 |
Aging Performance — Heat Aging (168 Hours @ 158°F)
| Property | Value | Test Method |
| Durometer / Hardness Change | +10 | ASTM 573 |
| Tensile Change | -25% max | ASTM 573 |
| Elongation Change | -25% max | ASTM 573 |
Environmental Performance
| Property | Value | Test Method |
| Ozone, 25 PPHM, 20% Strain, 48 Hours @ 104°F | No cracks | ASTM D1149 |
Regulatory / Compliance Data
| Property | Value | Test Method |
| AASHTO M251-06, Polyisoprene, Grade 2 | Meets | — |
| AASHTO LRFD Bridge Construction Specification, Section 18.2 | Meets | — |
Compliance
- AASHTO M251-06 (Plain and Laminated Elastomeric Bridge Bearing Pads, Polyisoprene, Grade 2) — Compliant
- AASHTO LRFD Bridge Construction Specification, Section 18.2 — Compliant
- Bridge bearing pads for pre-cast and pre-stressed concrete structural applications requiring AASHTO compliance and superior elastic recovery
- Bearing pads for buildings with structural steel beams or steel-reinforced concrete requiring thick-section natural rubber performance
- Isolation and load distribution pads for industrial machinery and heavy equipment foundations
- Railway tie pads requiring durable natural rubber elastomer performance with extended heat aging resistance
- Bearing and isolation elements in buildings, arenas, tunnels, and civil infrastructure in heavy-section applications
Common industries: Bridge and infrastructure constructio
Atlas Bearing™ 168 is a 60 Shore A natural rubber bearing pad engineered for bridge bearing and structural applications in pre-cast and pre-stressed concrete, steel-framed buildings, industrial machinery and heavy equipment foundations, railway tie pads, and civil infrastructure including arenas, tunnels, and buildings.
Natural rubber offers a combination of high tensile strength (2250 min. psi), high elongation (400% min.), and exceptional elastic recovery — reflected in the 25% max. compression set at 22 hours @ 158°F — that distinguishes it from the neoprene (CR) Atlas Bearing™ grades. This superior elastic recovery supports long-term load distribution and movement accommodation in structural bearing applications.
The material meets AASHTO M251-06 for plain and laminated elastomeric bridge bearing pads (polyisoprene, grade 2) and AASHTO LRFD bridge construction specification Section 18.2. Ozone resistance is confirmed at 25 PPHM, 20% strain, 48 hours at 104°F with no cracks per ASTM D1149. Heat aging at 158°F for 168 hours yields hardness change of +10, tensile change of -25% max., and elongation change of -25% max. per ASTM 573. Available in heavy-section thicknesses from 1/2″ to 1″.
Compliant with AASHTO M251-06 and AASHTO LRFD Section 18.2.
What differentiates Atlas Bearing™ 168 from the neoprene Atlas Bearing™ grades?
Atlas Bearing™ 168 uses a natural rubber polymer rather than neoprene (CR), delivering a compression set of 25% max. (22 hours @ 158°F) — significantly lower than the neoprene bearing grades at 35% max. — along with higher elongation (400% min. vs. 300–350% min.) and superior elastic recovery. Natural rubber also undergoes an extended heat aging protocol of 168 hours at 158°F, reflecting its distinct aging profile. It is available exclusively in heavy-section thicknesses (1/2" to 1"), suited for structural bridge bearing applications requiring thick, high-load-capacity pads.
Why is compression set an important consideration for elastomeric bearing pads?
Compression set measures how well an elastomer recovers its original thickness after sustained compression. In a bridge bearing or structural pad, high compression set means the pad permanently flattens under long-term structural load, reducing its ability to accommodate movement and distribute load evenly — potentially compromising structural integrity. Atlas Bearing™ 168 achieves 25% max. compression set (22 hours @ 158°F per ASTM D395B), the lowest of any Atlas Bearing™ grade, reflecting natural rubber's superior elastic recovery characteristics.
What is the cold temperature rating for Atlas Bearing™ 168?
Atlas Bearing™ 168 is rated to -40°F cold temperature per ASTM D2137, as listed on the TDS.
Is Atlas Bearing™ 168 suitable for bridge and structural infrastructure applications?
Yes. Atlas Bearing™ 168 meets AASHTO standard specification M251-06 for plain and laminated elastomeric bridge bearing pads (polyisoprene, grade 2) and AASHTO LRFD bridge construction specification Section 18.2, as stated on the TDS.
How should Atlas Bearing™ 168 be specified?
Specify grade (Atlas Bearing™ 168), thickness, compliance requirements (AASHTO M251-06 / AASHTO LRFD Section 18.2), dimensional tolerances, and finished format.
