Description

Chain No. 50SS · Pitch 15.875 mm · 5/8 inch

Stainless Steel Sprockets
SUS50B

Stepping up to 15.875 mm pitch — the SUS50B delivers meaningfully higher load capacity than the 40-series while retaining full 304 stainless corrosion immunity for demanding process-industry drive systems.

SUS50B — Higher Load Capacity in Full Stainless Construction

Within the stainless roller chain sprocket family, the SUS50B represents a meaningful step up in power transmission chain capacity from the 40-series. Its 15.875 mm pitch — equivalent to 5/8 inch — gives the No.50SS chain significantly greater cross-sectional area, and thus higher rated breaking load and working load, than the 12.7 mm pitch of the No.40SS family. For applications where a No.40SS drive is approaching its load limit, or where a designer wants working loads well below the chain’s rated capacity to achieve a longer service interval, the SUS50B provides the right upgrade path without sacrificing corrosion resistance or moving to a carbon steel construction.

The SUS designation confirms 304 austenitic stainless steel throughout, and all the material properties that make the smaller SUS series sprockets suitable for food-grade, pharmaceutical, and chemical process environments apply equally to the SUS50B. The passive chromium oxide film resists washdown chemicals and process vapors, the non-magnetic character avoids interference with metal detection systems, and the smooth as-machined surface meets the hygiene requirements of HACCP-audited facilities without needing coatings that could chip or peel into product streams. What changes with the 50B is the structural scale: tooth width increases to 8.7 mm, roller diameter to 10.16 mm, and the largest tooth count (40T) produces a part weighing 3.25 kg — noticeably heavier than its 40-series equivalent.

Hangzhou Ever-Power manufactures SUS50B sprockets across all 26 tooth counts from 10T through 40T, machined from solid 304 stainless bar. Standard bore finish is H7 tolerance with a Ra ≤ 0.8 μm surface. Keyway, set-screw, duplex strand, and fully custom configurations are produced from customer specifications with no minimum quantity restriction.

SUS50B Stainless Steel Sprocket No.50SS 15.875mm Pitch

Chain Parameters & Complete Dimensional Specifications

The four chain parameters for No.50SS chain establish the geometry of every SUS50B tooth profile. Notably, the roller diameter (10.16 mm) is slightly larger than the internal width (9.53 mm) — unlike the 40-series where both values match at 7.95 mm. This relationship between roller diameter and chain width is specific to the 50B pitch class and determines the exact root radius and flank clearance geometry machined into each tooth. Using sprockets designed for a different chain pitch, even one with similar dimensions, will produce poor engagement and rapid wear at the No.50SS pitch class.

Pitch (P)

15.875 mm

5/8 inch equivalent

Internal Width (W)

9.53 mm

Chain inner link spacing

Roller Dia. (Dr)

10.16 mm

Larger than inner width

Tooth Width (T)

8.7 mm

Simplex strand width

Complete SUS50B Dimensional Table — All 26 Sizes

All bore dimensions and hub measurements in millimeters; weight in kilograms. Stock bore = pilot bore as supplied; min./max. bore = achievable range through final machining.

Type	Teeth	OD Do (mm)	PCD Dp (mm)	Stock Bore	Min. Bore	Max. Bore	Hub BD	Hub BL	Wt. (kg)
SUS50B	10	58	51.37	9	11	22	40	25	0.27
SUS50B	11	64	56.35	14.5	16.5	28	45.5	25	0.33
SUS50B	12	69	61.34	14.5	16.5	30	50	25	0.41
SUS50B	13	74	66.34	14.5	16.5	32	51	25	0.46
SUS50B	14	79	71.34	14.5	16.5	32	52	25	0.52
SUS50B	15	84	76.35	14.5	16.5	35	57	25	0.62
SUS50B	16	89	81.37	14.5	16.5	40	62	25	0.72
SUS50B	17	94	86.39	14.5	16.5	45	67	25	0.83
SUS50B	18	100	91.42	14.5	16.5	48	72	28	1.00
SUS50B	19	105	96.45	14.5	16.5	48	73	28	1.10
SUS50B	20	110	101.48	14.5	16.5	48	73	28	1.20
SUS50B	21	115	106.51	14.5	16.5	48	73	28	1.20
SUS50B	22	120	111.55	16.5	18.5	48	73	28	1.30
SUS50B	23	125	116.58	16.5	18.5	48	73	28	1.30
SUS50B	24	130	121.62	16.5	18.5	48	73	28	1.40
SUS50B	25	135	126.66	16.5	18.5	48	73	28	1.50
SUS50B	26	140	131.70	16.5	18.5	48	73	28	1.50
SUS50B	27	145	136.74	16.5	18.5	48	73	28	1.50
SUS50B	28	150	141.79	16.5	18.5	48	73	28	1.60
SUS50B	30	161	151.87	16.5	18.5	48	73	28	1.80
SUS50B	32	171	161.96	16.5	18.5	48	73	28	1.90
SUS50B	34	181	172.05	16.5	18.5	48	73	28	2.10
SUS50B	35	186	177.10	16.5	18.5	48	73	28	2.20
SUS50B	36	191	182.14	16.5	18.5	55	83	35	2.85
SUS50B	38	201	192.24	16.5	18.5	55	83	35	3.05
SUS50B	40	211	202.33	22	24	55	83	35	3.25

304 Stainless Steel in Medium-to-Heavy Load Environments

A question that arises when specifying SUS50B for higher-load applications is whether 304 stainless steel is mechanically adequate for the duty. The answer lies in comparing the material’s properties against the actual working loads the drive imposes — not against the theoretical maximum tensile strength of induction-hardened carbon steel. At the 15.875 mm pitch and the load ratings for which No.50SS chain is designed, 304 stainless with its tensile strength of ≥ 515 MPa delivers a service factor well above 1.0 in most realistic applications. The tooth flank surface hardness (~180 HB as-machined) is lower than induction-hardened C45, but at the load levels and speeds where SUS50B is typically installed, this difference rarely translates to a visible difference in service life within a standard maintenance interval.

The more critical factor for most SUS50B installations is resistance to the operating environment rather than raw tensile strength. Corrosive vapors, wet washdown zones, and chemical exposure can destroy an unprotected carbon steel sprocket faster than normal tooth wear would, making the total lifetime of the carbon steel part shorter despite its higher intrinsic hardness. In these environments, the SUS50B’s corrosion immunity translates to a genuinely longer service life — often two to five times longer than a non-stainless alternative — which is the more relevant metric for a maintenance engineer calculating replacement costs and production downtime frequency.

SUS Series Pitch Progression — Load Capacity Context

SUS25B

6.35 mm

SUS35B

9.525 mm

SUS40B

12.7 mm

SUS50B ▶

15.875 mm

Tooth Profile Engineering & Hobbing Precision

At the 15.875 mm pitch level, tooth profile accuracy matters more than at smaller pitches for a straightforward mechanical reason: larger pitch chains transmit greater forces, and any geometry error in the tooth form concentrates those forces on a smaller contact area, accelerating wear non-linearly. A tooth profile error of 0.05 mm at 6.35 mm pitch (SUS25B) is proportionally significant; the same absolute error at 15.875 mm pitch (SUS50B) is a smaller fraction of the tooth geometry — but the absolute contact forces are higher, so the consequence of any error in terms of tooth face stress is greater. This is why our CNC hobbing tolerances are held the same across all pitch classes rather than relaxed for larger sprockets.

⚙️ Dedicated 50B Hobbing Tooling

CNC hobbing uses a dedicated No.50SS chain-specific tool geometry that matches the 10.16 mm roller diameter exactly. The same hob is used for all 26 tooth counts in the SUS50B range, eliminating cross-contamination of tolerance from tool wear between different pitch classes. Hobs are reconditioned on a defined cycle before reaching their wear limit, preventing tooth profile degradation from accumulating across production runs.

📐 Pitch Circle Tolerance Control

Pitch circle diameter tolerance is held to ±0.05 mm across the full range. Tooth-to-tooth spacing error is maintained below ±0.04 mm for all tooth counts. Both parameters are measured by optical comparator or CMM on each finished part before it is released for shipment. These tolerances are tighter than ISO sprocket accuracy grade IT8 requirements for this pitch class.

Material Verification → Bar turning → Blank concentricity check

304 stainless bar certified; blank turned in single clamping to bore/OD concentricity ≤ 0.02 mm. Blank diameter checked before proceeding to hobbing.

CNC Hobbing → Tooth profile verification → Pitch circle measurement

No.50SS hob generates all teeth in one pass. Pitch circle diameter checked immediately after hobbing with optical comparator. Parts outside ±0.05 mm are returned for review.

Bore reaming → Keyway → Final CMM → Marking → Packaging

Bore finished to H7, keyway broached to DIN 6885, CMM records bore and hub dimensions, laser mark applied, VCI wrap and carton for dispatch.

Industry Applications

The SUS50B occupies a niche in the industrial sprocket market where medium-to-heavy load capacity and full stainless construction are both required simultaneously. This combination is not needed everywhere, but in the sectors below it is the decisive specification criterion — and no compromise between lower-capacity stainless or higher-capacity carbon steel fully serves the application requirement.

🏭

Heavy Conveyor & Sorting Systems

Luggage handling systems at airports, parcel sorting conveyors, and heavy pallet conveying lines run continuous multi-shift duty with loads that exceed what No.40SS chain can reliably sustain. The SUS50B step up in pitch provides the required capacity while maintaining corrosion resistance in outdoor-adjacent or washdown-zone installations where weather and cleaning expose the drive hardware to moisture and detergent on a daily basis.

🐟

Seafood & Fish Processing

Whole-fish processing lines, fillet conveyors, and prawn sorting machines carry heavier product loads than comparable equipment in lighter food sectors. Combined with the saline, high-humidity environment of a fish processing plant — one of the most corrosive operating conditions in any food industry segment — the SUS50B’s higher load capacity and stainless construction make it the standard drive component specification for equipment designed to last through multi-year production cycles without major drive system overhaul.

🍺

Brewery & Distillery Equipment

Keg washers, barrel conveyors, and tank agitator drives in breweries and distilleries move heavy loads through environments with CO₂ vapors, caustic cleaning solutions, and spilled process liquids. The 50B pitch class handles the heavier mechanical demands of keg and barrel handling while the stainless construction holds up through decades of operation in a facility that never truly dries out between shifts.

🏗️

Construction & Mining Equipment (Wet Zones)

Underground mining conveyors operating in wet headings, slurry pump drives, and aggregate washing plant chain mechanisms face both heavy loads and constant water and mineral acid exposure. SUS50B sprockets in these applications outlast zinc-plated or painted carbon steel equivalents significantly, reducing the frequency of below-ground or hard-to-access maintenance interventions that carry disproportionate safety and productivity costs.

🌊

Water & Wastewater Treatment Infrastructure

Sludge conveyor drives, bar screen mechanisms, and clarifier raking systems in water treatment plants operate continuously under load in permanently humid, occasionally submerged environments with hydrogen sulfide and ammonia exposure. The SUS50B’s higher pitch capacity suits these heavy slow-speed drives while the stainless material eliminates the corrosion failures that are the primary cause of unplanned plant shutdowns in this sector.

🧴

Bulk Chemical Processing & Filling Lines

Drum filling lines, IBC (intermediate bulk container) handling conveyors, and bulk bag filling equipment in chemical plants move heavy loads and face acid, alkali, or solvent splash continuously. At this scale, the No.50SS chain pitch provides the structural capacity needed, and the SUS50B sprocket materials meet the chemical resistance requirements that standard carbon steel or even zinc-coated alternatives cannot satisfy reliably.

SUS50B Stainless Steel Sprocket Heavy Duty Industrial Installation

Duplex Strand & Custom Configuration Options

The SUS50B range is produced as simplex (single-strand) as the catalogue standard, but duplex and triplex configurations are available on order for applications that require higher load capacity at the same pitch diameter and installation envelope. Moving from simplex to duplex effectively doubles the chain’s working load without changing the sprocket tooth count or centre distance — a significant design option when upgrading an existing drive rather than redesigning the entire machine layout. All bore, keyway, and hub customization options available on simplex SUS50B are equally applicable to duplex and triplex configurations.

🔗 Simplex Standard

Tooth width 8.7 mm. Covers full 10T–40T range from production stock or short lead time. Standard bore, keyway, and set-screw options. Lead time 3–7 business days for common sizes.

🔗🔗 Duplex to Order

Double tooth face width for two parallel No.50SS strands. Same tooth profile and pitch circle as simplex for the same tooth count — only the face width changes. Specify strand count, teeth, bore, hub length. Lead time 7–14 business days.

📐 Full Custom OEM

Non-standard teeth counts, split sprockets, flanged hubs, taper-lock bores, or reverse-engineered replacements. Drawing approval before production. No minimum quantity. First-article inspection report with delivery.

Upgrade path tip: If your current SUS40B simplex drive is running near its load limit, upgrading to SUS50B simplex adds approximately 40–50% more chain working load capacity at the same general speed range. If even more capacity is needed, moving to SUS50B duplex multiplies capacity again without requiring a centre distance change. Discuss your load and speed requirements with our engineering team for a recommendation before placing an order.

Factory Capability & Quality Standards

As a direct sprocket wheel manufacturer with complete in-house production from bar stock to finished, inspected, and marked part, Hangzhou Ever-Power maintains the process control and quality documentation that international OEM and MRO customers need — without the lead times and markups of a trading company intermediary.

Hangzhou Ever-Power SUS50B Sprocket Manufacturing Facility

🔬 CMM Inspection on Every Part

100% dimensional inspection — not sampling — on pitch circle diameter, bore, and hub dimensions. Parts outside tolerance are quarantined before dispatch, not discovered in the field.

📋 Material Traceability

EN 10204 3.1 mill certificates available on request, linking finished parts to specific steel heats. Required for regulated procurement categories in food, pharma, and nuclear sectors.

⚡ 3–7 Day Standard Lead Time

Semi-finished stock on common SUS50B tooth counts means bore finishing and keyway operations can complete quickly. Urgent replacement orders for production shutdowns are prioritized where schedule allows.

🌐 50+ Export Destinations

Export documentation for all major import markets is prepared in-house: commercial invoice, packing list, certificate of origin, and HS code classification for roller chain sprockets.

Request SUS50B Quote

How to Place Your Order

Standard SUS50B orders require only three inputs — tooth count, bore diameter, and quantity — to generate a quotation. Custom configurations need a brief spec sheet or dimensioned drawing. Quotations for standard sizes come back within 24 hours; engineering review for custom parts takes 24–48 hours depending on complexity. Reach us at [email protected], by phone at +86-571-88220653, or through our contact page.

Submit Inquiry

Teeth, bore, strand type, quantity. Email, phone, or contact form.

Receive Quote

Price, lead time, and payment terms within 24 hours.

Confirm & Produce

PO confirms production. Custom parts include drawing sign-off.

Ship with Docs

Dispatched with inspection report and material certificate on request.

Hangzhou Ever-Power Sprocket Chain Co., Ltd.

📍 Shenhua Road, Hangzhou, China
📞 +86-571-88220653
✉️ [email protected]

Frequently Asked Questions

Common questions about SUS50B stainless steel sprockets.

1. How does the SUS50B relate to the ANSI #50 standard?
+

The SUS50B’s 15.875 mm pitch corresponds exactly to the ANSI #50 chain pitch (5/8 inch). The roller diameter of 10.16 mm (13/32 inch) and internal width of 9.53 mm (3/8 inch) also match ANSI #50 chain specifications. A correctly machined SUS50B sprocket will engage both No.50SS (JIS stainless designation) and standard ANSI #50 chain. When replacing an existing ANSI #50 sprocket with a SUS50B, confirm the tooth count, bore diameter, and hub length match the original before ordering.

2. Why do the stock bore values increase at certain teeth counts?
+

Stock bore sizes are set at convenient round dimensions that match the pilot bore used in production, taking into account the hub OD at each tooth count. As hub diameter increases with tooth count, the allowable bore range widens while still maintaining adequate wall thickness. The jump from a stock bore of 9 mm at 10T to 14.5 mm at 11T–21T reflects the hub OD stepping up significantly across that range, allowing a larger pre-machined bore without compromising hub strength.

3. Can SUS50B sprockets handle shock loading in conveying systems?
+

304 stainless has an elongation to failure of ≥ 40%, making it a ductile material that absorbs shock loads through plastic deformation rather than brittle fracture. For moderate shock loading — conveyor start-stop cycles, product drop impacts — SUS50B sprockets perform reliably. For severe repetitive shock loading, such as bucket elevator head-shaft drives with heavy impact, consider applying a service factor of 1.5–2.0 when calculating the required chain capacity to ensure adequate working load margin. Contact our team to review the application if severe shock is a concern.

4. Is it possible to get SUS50B sprockets with a taper-lock bore?
+

Yes — taper-lock bore configurations are produced as custom orders for SUS50B sprockets on tooth counts where hub geometry allows sufficient wall thickness for the taper-lock insert pocket. This mounting style is common on larger industrial drives where sprocket removal for maintenance needs to be fast and repeatable. Specify the required taper-lock bush size (e.g. 1610, 2012, 2517) when requesting a quotation, and we will confirm compatibility with the chosen tooth count and bore diameter.

5. What lubrication is recommended for SUS50B drives in food environments?
+

NSF H1-registered food-grade chain lubricants are required wherever lubricant could come into incidental contact with food products. These lubricants are formulated for stainless steel compatibility and will not stain or chemically attack the 304 stainless surface. For drives operating in washdown zones, choose a lubricant with good water-wash resistance — light penetrating oils applied frequently are less suitable than heavier food-grade greases or tackified chain lubricants that remain on the chain under jet washing. Apply lubrication after washdown cycles rather than before, so the lubricant film is not immediately stripped away.