Heavy Duty Series Roller Chains

H Series

and BH / BHF Non-Standard

9.525 to 76.2mm

Pitch Range

Up to 1,650 kN

Triplex Breaking Load

ISO 9001

Certified Quality

Korea Ever-Power heavy duty series roller chains are an uprated variant of the standard short pitch roller chain range, designed for applications where the operating load, shock loading severity, or duty cycle exceeds what the standard A series can comfortably handle at the same pitch. The heavy duty designation refers to thicker link plates - typically 25% to 40% heavier than the standard A series plate at the same pitch - combined with larger diameter pins and in some sizes an increased inner width, all while maintaining the same pitch so that the chain can run on standard pitch sprockets without any modification to the sprocket or drive configuration.

The EP H series covers chain sizes *35H through 240H in simplex (single strand, suffix -1), duplex (two strand, suffix -2), and triplex (three strand, suffix -3) configurations. The H suffix is the industry-standard designation for the heavy duty plate geometry: a 35H chain has the same 9.525 mm pitch and the same roller diameter as a standard 35 chain, but the link plates are thicker, giving it a higher tensile strength rating and a higher fatigue life under repeated loading. This matters in applications such as agricultural harvester main drives, log deck drives, packaging machine main drives, and general industrial drives that start and stop under load, experience vibration from coupled machinery, or must handle the shock peaks generated when slack suddenly comes out of the chain during load reversal.

Beyond the standard H series, Korea Ever-Power manufactures a comprehensive range of non-standard heavy duty chains under the BH and BHF designations. These are chains developed for specific OEM applications where neither the standard A series nor the standard H series geometry exactly matches the sprocket tooth form or structural requirement of the original equipment. The BH range includes straight side plate variants (where the inner and outer plates are the same flat profile rather than the usual waisted figure-eight shape), flanged plate variants for guide track applications, and combination chains with mixed roller and bush positions for specific machine functions. Bush chains within both the H series and the BH range are marked with an asterisk (*) - for these chains the d1 dimension in the specification table refers to the external diameter of the bush rather than an outer roller diameter, because no separate outer roller is fitted.

The Korea Ever-Power heavy duty chain production line uses the same cold-forming and heat treatment processes as the A series, with through-hardened alloy steel pins, case-hardened bushes, and heat-treated plates. The heavier plate sections in the H series require longer heat treatment cycles to achieve uniform core properties, and the larger pin diameters require closer dimensional control in grinding to maintain the correct pin-to-bush clearance for good lubrication film retention. Pre-loading is applied to every assembled H series chain before pitch measurement to eliminate installation elongation, in the same manner as the standard A series range. Connecting links in the H series use cotter pin or split pin retention rather than the spring clip used in lighter standard chains, reflecting the higher joint loading in heavy duty service.

When to Choose Heavy Duty Series Over Standard A Series

Agricultural Machinery

EP 40H through 100H simplex chains are the standard specification for combine harvester main drives, straw walker drives, and grain auger drives. The 40H-1 is the single most widely used heavy duty chain in agricultural machinery worldwide. The higher plate thickness absorbs the shock loading from crop ingestion and from stones entering the feed mechanism, giving field service life approximately 40% longer than the equivalent standard 40 chain under the same conditions.

Press and Punch Drives

Mechanical presses, punch presses, and stamping machines transmit a sharp shock pulse through the drive chain at the moment of punch contact and punch breakthrough. EP 80H-1, 100H-1, and 120H-1 simplex and duplex chains are commonly specified for press main drives and flywheel drives. The heavier plate section resists the fatigue cracking that would otherwise develop at the pin hole edge under repeated high-amplitude stress cycles.

Mining and Quarry

EP 120H through 240H chains for primary crusher drive chains, vibrating screen drives, and apron feeder drive chains in mining and quarry plant. Duplex 120H-2 and 160H-2 are the standard size range for jaw crusher main drives. The H series is also specified for coal preparation plant drives, where water and coal dust contaminate the lubrication and the drive operates under variable load from the coal feed rate fluctuation.

Sugar Industry

Sugar mill main drives and cane elevator drives use EP heavy duty chains in the 100H to 200H range. The juice environment is highly corrosive to steel chain, and the cane ingestion load is unpredictable - a stone or dense root clump entering the mill can momentarily spike the load to several times the rated running load. The H series provides the combination of corrosion resistance (through correct lubrication specification) and fatigue strength required for these demanding tropical mill conditions.

Matching sprockets for every EP chain size are available through our partner site sprocket-chain.net. All ANSI B29.1 and ISO 606 tooth forms, simplex through 8-strand, C45 carbon steel and alloy steel, pilot bore and finished bore hub designs.

View Matching Sprockets →

★★★★★

"We upgraded our combine harvester main drive from standard 80 chain to EP 80H-1. The previous standard chains were needing replacement every harvest season. The 80H chains have now run for three full harvests with elongation at 1.6% - well within the 3% replacement threshold. The cost per season is significantly lower even though the EP 80H chain has a higher purchase price."

B.K., Fleet Engineer
Ukraine - Large Grain Farm

★★★★★

"Our jaw crusher main drive uses 120H-2 duplex chains. We had a history of fatigue plate fractures with previous supplier chains approximately every 8 months. EP 120H-2 chains have been running for 19 months without any plate fracture or connecting link failure. The improvement is directly attributable to the consistent plate hardness across the batch - no soft spots."

A.O., Maintenance Superintendent
South Africa - Aggregate Quarry

★★★★★

"We needed a 12BHF2 non-standard chain to replace the original OEM specification on our packaging machine elevator drive. EP confirmed the chain from our EP chain number, delivered 5 complete circuit lengths cut and fitted with connecting links within 9 working days. The chains matched the original dimensions exactly and fitted without adjustment."

P.W., Engineering Manager
Germany - Food Packaging Plant

★★★★★

"Our sugar mill drive specifies 160H-1 simplex chains for the cane elevator. The EP chains have been running through two grinding seasons in a highly corrosive juice environment with correct lubrication. Service life has exceeded our planned replacement interval and our maintenance team now standardises on EP H series across all mill drives."

R.F., Chief Engineer
Thailand - Sugar Mill

Request a Quotation for EP Heavy Duty Roller Chains

Provide the chain designation (H series ANSI number with strand suffix, or EP-BH/BHF chain number), quantity in metres or link count, and whether attachment or connecting link specification is needed. For non-standard BH/BHF chains, the EP chain number from the table above or a dimensional sample is sufficient for quotation. Our team responds within one business day.