12B‑Series: DIN 8187 / ISO/R 606 Standard

Sprocket & Chain Dimensional Data

Full Dimensional Table Z8–Z125

Material Quality & Heat Treatment

Every 12B sprocket manufactured by Ever Power is produced from C45 medium‑carbon structural steel, a grade recognised across British and European engineering for its excellent balance of hardness and toughness. With a nominal carbon content of 0.42–0.50%, C45 steel offers tensile strength typically exceeding 700 N/mm² after normalising, ensuring the 12B sprocket tooth profile maintains its geometry under high cyclic loads. The material specification is consistent across the entire range, from the compact Z8 simplex variant to the large‑diameter Z125 weld‑on hub 12B triplex sprocket. Surface hardness is optimised during finishing to resist the sliding and impact contact inherent in roller chain engagement, extending service life and reducing unplanned downtime on production lines. For customers requiring additional surface protection, Ever Power can arrange zinc phosphate treatment, black oxide finishing, or electrolytic zinc plating to order — simply mention the requirement when requesting a quotation for your 12B DIN 8187 sprocket.

Dimensional Accuracy & Standard Compliance

Compliance with DIN 8187 and ISO/R 606 is not merely a commercial claim but a manufacturing commitment upheld through rigorous in‑process inspection. The 12B roller chain standard specifies a pitch of 19.05 mm, an inner width of 11.68 mm, and a roller diameter of 12.07 mm. Every 12B sprocket tooth profile — with tooth radius r₂ = 19 mm, radius width C = 2 mm, and tooth width B₁ = 11.1 mm for simplex — is machined and verified against these parameters. Duplex and triplex variants carry the corresponding multi‑row tooth widths (B₂ = 30.3 mm and B₃ = 49.8 mm respectively) with consistent inter‑row spacing. Tip diameter (de) and pitch circle diameter (dp) tolerances are held tightly across the Z8 to Z125 range, ensuring drop‑in interchangeability and predictable engagement geometry. British OEM customers can specify the 12B DIN 8187 sprocket with full confidence that drawing dimensions and received components will correspond exactly.

Hub Configurations: Standard & Weld‑On

The 12B sprocket range is offered in two principal hub configurations to accommodate the widest possible range of installation scenarios. Standard‑hub sprockets (Z8 through Z40) feature a machined boss bored to a customer‑specified shaft diameter, with internal keyway cut to British Standard or DIN tolerances as required. Hub lengths (A dimension) range from 30 mm at the smallest sizes up to 70 mm on larger sprockets, providing adequate bearing contact for substantial shaft engagement. From Z41 upward, a weld‑on hub construction is used, indicated by the asterisk (*) marker in the dimensional tables. The weld‑on 12B sprocket is supplied as a plate with integrated central boss ready for welding to a shaft, stub, or fabricated sub‑assembly — a configuration widely favoured in heavy conveyor applications across the Yorkshire and Humber region’s manufacturing base. Hub diameter (dm) and bore diameter (D) dimensions are standardised for each weld‑on size group, simplifying integration and enabling like‑for‑like replacement across maintenance programmes.

Supply Range & UK Stock Availability

Ever Power maintains a broad stockholding of 12B‑1 simplex, 12B‑2 duplex, and 12B‑3 triplex sprockets across the most frequently demanded tooth counts, with the full Z8–Z125 range available to order for scheduled or urgent deliveries into the UK. Popular sizes for food processing machinery in Yorkshire, packaging equipment in the West Midlands, and agricultural drives in East Anglia are held in depth to support both planned maintenance programmes and emergency breakdown requirements. Standard lead times for non‑stock sizes are typically 7‑14 working days ex‑works, with express manufacturing available for critical shutdowns. All 12B DIN 8187 sprockets are despatched with material certification and dimensional inspection records on request. Minimum order quantities are flexible for B2B customers, with volume pricing available for regular repeat requirements. Ever Power’s UK‑focused account management team can support you with technical drawings, CAD data, and sourcing advice for companion 12B roller chain to complete your drive package.

Full Dimensional Table — Z8 to Z125 (all dimensions in mm)

* = Weld‑on hub

DIN 8187 Certified Precision

Every 12B DIN 8187 sprocket meets the full dimensional and tolerance requirements of both DIN 8187 and ISO/R 606, ensuring interchangeability across all chain brands and drive systems used in British industry.

C45 Steel Throughout

Medium‑carbon C45 steel provides the optimum balance of strength, toughness, and machinability. Higher hardness than mild steel, better toughness than high‑carbon grades — the preferred specification for 12B sprocket applications across engineering sectors.

Full Range Z8–Z125

With simplex, duplex, and triplex variants from 8 to 125 teeth, the 12B sprocket range covers virtually every ratio and load requirement. Single‑source procurement for complete drive systems saves time and simplifies quality control.

Standard & Weld‑On Hub Options

Both machined‑bore and weld‑on hub configurations are available, the latter indicated by * in the dimensional tables. Weld‑on 12B sprockets (Z41–Z125) enable integration into fabricated structures commonly found in heavy‑duty conveyor and hoist applications.

UK‑Focused B2B Supply

Dedicated account management for UK buyers, with stock levels calibrated to British maintenance cycles. Fast despatch to Yorkshire, the Midlands, East Anglia, Wales, and Scotland. Material certs and inspection records available on request for regulated industries.

Custom Specification Available

Non‑standard bores, keyways, set‑screw holes, and surface treatments can be specified to order. OEM customers with bespoke 12B sprocket requirements are invited to submit technical drawings for quotation. Minimum quantities are negotiable for volume schedules.

Food Processing

Conveyor and slat‑chain drives in abattoirs, bakeries, and poultry plants across Yorkshire and the North. The 12B simplex sprocket is the standard choice for hygienic single‑strand conveyor lines.

Agricultural Machinery

Grain handling, root crop elevators, and PTO‑driven implements across East Anglia and the Fens. 12B duplex sprockets are widely used in header drives, straw walkers, and cleaning‑shoe assemblies.

Packaging & Print

Index drives, feed mechanisms, and transport chains in packaging lines throughout the West Midlands and the South East. Simplex 12B sprockets with precision bores are specified for low‑backlash indexing applications.

Mining & Quarrying

High‑load conveyor drives, scraper chains, and pan conveyors in Welsh and Northern England quarries. 12B triplex weld‑on hub sprockets are often preferred for maximum load capacity without shaft machining.

Automotive & Engineering

Transfer lines, overhead conveyor systems, and assembly equipment in Midlands manufacturing plants. The 12B DIN 8187 sprocket’s broad availability makes it the default for new OEM designs and legacy replacements alike.

Waste & Recycling

Shredder drives, trommel feeds, and baling press chains in waste processing facilities nationwide. The robust C45 construction and generous hub dimensions of the 12B sprocket make it suitable for shock and surge loading.

We’ve been specifying Ever Power 12B simplex sprockets for our conveyor rebuild programme in our Yorkshire facility for three years. Dimensional accuracy is spot‑on every batch, and the material certs land in the inbox before the goods. That’s the standard we need in a food‑grade environment.

Harvest season means no time for supplier problems. We ordered a batch of 12B duplex weld‑on sprockets for our grain elevator drives and they arrived two days later, perfectly to DIN 8187 spec. The weld‑on hub construction saved our fitter a full day of shaft machining. Excellent service from the team.

Our packaging lines run three shifts a day and downtime is expensive. Switching to Ever Power 12B triplex sprockets on the main index drives reduced our chain wear noticeably. The tooth profile is clean, the bore tolerances are tight, and the price is competitive against our previous UK supplier. We won’t be changing.

Customisation Capabilities

What is a 12B sprocket and what chain does it use?

A 12B sprocket is a toothed wheel designed to engage with 12B roller chain, which has a pitch of 19.05 mm (3/4 inch) and an inner width of 11.68 mm, with a roller diameter of 12.07 mm. The designation “12B” follows the DIN 8187 and ISO/R 606 classification system for European‑standard roller chains. The suffix indicates the series: 12B‑1 for simplex (single strand), 12B‑2 for duplex (double strand), and 12B‑3 for triplex (triple strand). Sprockets are available from Z8 to Z125 teeth, with the pitch circle diameter calculated from the tooth count and chain pitch. It is widely used across food processing, agricultural machinery, packaging, and general engineering throughout the UK.

Is a DIN 8187 sprocket the same as an ISO 606 sprocket?

Yes, for practical engineering purposes the DIN 8187 sprocket and ISO/R 606 sprocket are fully interchangeable. DIN 8187 is the German standard for roller chains of the “B” series, while ISO/R 606 is the corresponding international standard. Both specify identical pitch dimensions, roller diameters, inner widths, and tooth profile geometry. The B‑series chain — including 12B — is the predominant standard in Europe and the UK, as distinct from the American‑standard ANSI/ASME B29.1 chains used in North America. All Ever Power 12B DIN 8187 sprockets fully comply with both standards and are designed to work with any conforming 12B roller chain, regardless of manufacturer.

What does the asterisk (*) mean in the 12B sprocket dimensional table?

The asterisk (*) in the dimensional table denotes a weld‑on hub configuration. From Z41 upwards, the sprocket body becomes too large for an economical machined‑bore hub, so the design switches to a plate with a separate central boss that is welded to a shaft or fabricated sub‑assembly. The weld‑on hub values in the table represent the outer hub diameter (dm), the bore pre‑weld (D), and the hub length (A). For Z41–Z64 simplex 12B sprockets, for example, the weld‑on hub is dm=110 mm, D₁=20 mm, A=56 mm. This construction is standard in heavy conveyor and elevator applications. If you require a machined bore on larger sprocket sizes, please contact our team to discuss custom fabrication options.

How do I choose between 12B‑1 simplex, 12B‑2 duplex, and 12B‑3 triplex sprockets?

The choice between simplex, duplex, and triplex 12B sprockets depends primarily on the power or load to be transmitted and the available shaft centre distance. A 12B‑1 simplex sprocket is the lightest and narrowest option, suitable for moderate loads on single‑strand drives. Fitting 12B‑2 duplex chain and matching duplex sprockets approximately doubles the power capacity for the same pitch diameter, while 12B‑3 triplex triples it. As a general rule, designers choose the simplest (smallest) configuration that meets the duty, as duplex and triplex drives require more precise alignment and generate higher transverse loads on bearings. If you have a power requirement and speed data, Ever Power’s technical team can advise on the optimal 12B sprocket selection for your application.

Can I get a 12B sprocket with a non‑standard bore or taper‑lock connection?

Yes, Ever Power supplies 12B sprockets with custom bore specifications, including non‑standard diameters, H7 tolerance bores, keyway and keyseating to DIN 6885/BS 4235 profiles, and taper‑lock bore inserts to popular SPT and Taper‑Lock bushing patterns (1008 through 5050 and beyond). Simply provide your shaft diameter, keyway dimensions, and any torque‑limiting requirements when requesting a quotation. For taper‑lock 12B sprockets, we can advise on the most appropriate bushing size based on the hub diameter and bore range. Lead times for custom‑machined 12B sprockets are typically 5–10 working days from drawing approval, with express options available for urgent breakdowns.

What is the material of the 12B sprocket and is it suitable for food processing environments?

Standard 12B sprockets are manufactured from C45 medium‑carbon steel. While this provides excellent mechanical performance, it is susceptible to corrosion if exposed to moisture or aggressive wash‑down chemicals without surface protection. For food processing environments in Yorkshire, the North West, or anywhere subject to regular CIP (clean‑in‑place) procedures, we recommend specifying zinc phosphate coating, electroless nickel plating, or — for maximum corrosion resistance — stainless steel. Ever Power can supply 12B sprockets in SS304 or SS316 on request for food‑grade applications. Please contact sales@gear‑chains.com with your hygiene and material requirements for a tailored recommendation.

How quickly can Ever Power deliver 12B sprockets to addresses in the UK?

Ever Power holds a core stock of the most commonly requested 12B sprocket sizes — particularly simplex and duplex variants in the Z15 to Z57 range — for prompt despatch to UK destinations. Standard in‑stock orders confirmed before 12:00 noon Monday to Friday are typically despatched same day for next‑working‑day delivery to mainland England, Scotland, and Wales, including Yorkshire, the Midlands, and East Anglia. Orders for non‑stock or large‑quantity sprockets are typically fulfilled within 7–14 working days ex‑works. Custom‑machined and surface‑treated variants require additional lead time depending on specification complexity. For breakdown situations, contact our team directly at sales@gear‑chains.com to discuss emergency procurement options.