Description
Rubber Top Chain — 20B-G1
20B-G1 rubber top chain delivers the load capacity of the ISO 20B-1 roller chain base — 95 kN minimum tensile — with a G1 rubber top profile for non-marking conveying of the heaviest product formats on European-standard heavy industrial equipment.
Product Overview
The ISO 20B-1 base chain at 31.75mm pitch provides a notably higher minimum tensile rating than its ANSI equivalent (20A, 87.5 kN) due to different plate thickness and pin specifications within the ISO standard at this pitch — 95 kN versus 87.5 kN. For European equipment operating at the upper end of the 31.75mm pitch load range, specifying ISO 20B-G1 rather than ANSI 20A-G1 provides an additional safety margin within the same pitch envelope, without requiring a move to a larger and heavier pitch chain.
European glass processing equipment, natural stone conveying lines, and heavy panel manufacturing plants that were originally designed to ISO 20B-1 chain specifications will require ISO 20B-G1 rubber top chain as the correct replacement specification — the ANSI 20A-G1 chain cannot be substituted because the roller diameter, inner plate width, and pin dimensions differ between standards, resulting in incorrect sprocket engagement. The non-marking rubber top function of the 20B-G1 is identical to the equivalent ANSI chain in all practical performance characteristics.
20B-G1 — G1 narrow rubber top on ISO 20B-1 (B-series) base
Specification — 20B-G1
| Chain No. |
Pitch P (mm) |
Roller Ø (mm) |
Inner Width (mm) |
Pin Ø (mm) |
Pin Length (mm) |
Plate Depth (mm) |
Rubber W (mm) |
Rubber H (mm) |
Overall W (mm) |
Q min (kN) |
Weight (kg/m) |
| 20B-G1 |
31.750 |
19.05 |
19.56 |
10.19 |
41.30 |
26.42 |
48.0 |
16.0 |
62.0 |
95.0 |
3.70 |
Rubber top chain in production conveyor environment
Rubber Profile and Material Properties
20B-G1 rubber top chains follow the same compound specifications as the rest of the rubber top series: 75–80 Shore A NBR standard, silicone for elevated temperatures, 90 Shore A abrasion-resistant for stone and concrete, and food-grade NBR with H1 lubrication where required. At the ISO 20B pitch, the higher tensile rating compared to ANSI 20A at the same pitch reflects the thicker plates and larger pin specified in the ISO standard at 31.75mm pitch — the rubber top profile dimensions are the same as for ANSI 20A-G1 at the same nominal pitch.
Core Performance Advantages
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Positive Non-Slip Grip
The vulcanised rubber surface grips product bases firmly at conveyor accelerations and on inclined sections where smooth-surface chains allow slippage — eliminating the positioning errors and product damage that result from uncontrolled sliding.
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Measurable Noise Reduction
Rubber’s damping properties absorb the micro-impacts at each sprocket link engagement, reducing conveyor operating noise at the product contact surface. In facilities with noise regulations, this can be a compliance factor.
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Surface-Safe Product Handling
Direct contact between bare steel chain and finished product surfaces causes scratching, denting, and marking. The rubber layer completely eliminates steel-to-product contact, maintaining surface integrity through the full conveyor run.
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Standard Sprocket Compatibility
The base chain dimensions are fully standard — the same sprockets used for the equivalent standard roller chain work without modification for the rubber top version. No hardware changes required for retrofitting.
Application Areas
Industrial conveyor application for 20B-G1
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Heavy Stone Processing — European Equipment
Large granite and marble slab conveyors built to ISO standards in European stone processing plants require ISO 20B-G1 as the correct rubber top replacement specification.
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Architectural Glass — European Machinery
Jumbo glass production lines in European float glass and processing plants using ISO-standard chain conveyors require ISO 20B-G1 for correct sprocket engagement with existing equipment.
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Heavy Structural Wood — European Lines
CLT, glulam, and heavy engineered wood product lines with ISO-standard conveyor chains use 20B-G1 for non-marking transport of structural wood with visible finish surfaces.
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Heavy Precast Concrete — EU Plants
Large architectural precast facade panels on ISO-standard European production equipment require the ISO 20B-G1 specification for both load capacity and non-marking surface contact.
Rubber top chain on production line
Related Components We Supply
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Matched Sprockets — ISO 20B-1 (B-series)
Standard sprockets in the pitch matching 20B-G1. No special tooth form needed — standard ISO 20B-1 (B-series) sprockets engage rubber top chains correctly at the roller-to-tooth interface.
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Rubber Top Connecting Links
Connecting links with matching rubber top profile for a smooth, uninterrupted conveying surface at the chain join point.
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Replacement Rubber Top Outer Link Sets
Individual outer link plate assemblies with vulcanised rubber profiles for field repair of worn sections without replacing the full chain.
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UHMWPE Guide Rails
Low-friction polyethylene guide profiles reducing lateral wear on rubber edges in side-guided conveyor configurations.
Customer Reviews
★★★★★
“Our conveyor system was designed to ISO 20B-1 specification throughout. When we needed rubber top chains for our polished granite slab line, 20B-G1 was the only correct specification — the ANSI equivalent would not fit our sprockets. Quality here is excellent and the rubber profile is consistent. We have run 30 months without delamination on the chains installed at our last annual maintenance.”
A
Andreas Schmidt
Technical Director — Munich Stone Processing Plant
★★★★★
“Specified ISO 20B-G1 for our jumbo glass conveyor handling 6,000mm lites. The chain capacity is more than adequate for our panel weights and the rubber top eliminates the surface stress marks that were occurring with our previous bare-steel chain at the same conveying speed. Documentation package was complete for our ISO 9001 internal audit.”
S
Sophie Legrand
Production Manager — Lyon Glass Processing SAS
★★★★★
“Our CLT element conveyor uses ISO 20B-G1 rubber top chains for handling 12m structural elements. The non-marking contact is essential for the visible wood surfaces of our architectural CLT products. The load capacity is well within margin even for our heaviest elements. Reorder process is straightforward and delivery is reliable.”
P
Pieter van der Berg
Plant Engineer — Amsterdam Heavy Panel Plant
Frequently Asked Questions
Why does ISO 20B have a higher tensile rating than ANSI 20A at the same pitch?+
Both chains have 31.75mm pitch, but ISO 20B-1 specifies thicker link plates and a larger pin diameter than ANSI #100 (20A) at this pitch. The ISO 20B inner plate thickness is 4.50mm vs approximately 3.96mm for ANSI #100; pin diameter is 10.19mm vs 9.53mm. These differences in cross-section deliver the higher tensile rating (95 kN vs 87.5 kN) within the same pitch envelope. The dimensional differences also mean the two chains require different sprockets — they cannot be substituted for each other.
How do I confirm whether my equipment uses ANSI or ISO 20-series chain?+
Check the chain number stamped on the outer link plate of your existing chain. ISO 20B-1 will be marked ’20B-1′ or ‘BS 20B’. ANSI #100 will be marked ‘100-1’ or ‘ANSI 100’. Alternatively, measure the roller outer diameter: ISO 20B-1 uses a 19.05mm roller (same as ANSI #100) but has a 19.56mm inner width, while ANSI #100 has a 18.90mm inner width. The inner width measurement is the most reliable way to distinguish between the two at the same pitch.
Is 20B-G1 available with self-lubricating bushings?+
Yes — ISO 20B-G1 with SLR sintered oil-impregnated bushings is available for long-run heavy industrial conveyors where manual lubrication access is restricted. Service life under moderate load at #100 pitch is typically 2,500–4,000 operating hours before the oil reservoir is depleted.
Are food-grade versions of 20B-G1 available?+
Yes — 316L stainless steel 20B-G1 with food-grade NBR rubber and H1 lubricant is available for food processing applications at this pitch. At the 20B pitch, food processing applications are typically in heavy meat, fish, or bulk food conveying where very high loads and large product formats require the heavy-pitch chain capacity. Full FDA and EU food contact compliance documentation is provided with every food-grade order.
What is the minimum order for 20B-G1 rubber top chains?+
There is no minimum order for standard 20B-G1 in stock lengths. For custom rubber compound specifications or non-standard configurations, a minimum of 5 metres applies. At this pitch, chains are typically ordered in full conveyor lengths — we can calculate the required chain length from your conveyor geometry if you provide the sprocket centre distances, sprocket tooth counts, and total conveyor path length.
Get in Touch
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Send us your chain specification and annual volume. Standard enquiries receive a quotation within 2 business days.
Further reading: standard vs heavy series roller chain capacity explained.
