Welded-steel-type Mill Chains with Attachment

Raydafon welded steel mill chains with attachments are manufactured to ASME B29.16M and ISO 6972 standards. Chain numbers range from WR78/WH78 (66.27mm pitch) to WR150/WH150 (153.67mm pitch), with minimum tensile strength from 93.4 kN (WR78) to 820 kN (WR155/WH155). Two construction series are available: WR series with heat-treated pins and bushes only, and WH series with all components (pins, bushes and plates) fully heat-treated for maximum wear life and strength. Standard attachments include A1, A2, A22, F2, F4, K1, K2 and W1 — all field-weldable for easy installation. Typical applications include forestry log hauling, sawmill chip conveying, pulp and paper processing, plywood handling, and bulk material handling where high shock loads and abrasion are present. Sprockets with 5 to 36 teeth are available. Send chain number, series, attachment type and quantity for a confirmed quotation within 24 working hours.

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Product Description

What Is a Welded Steel Mill Chain and How Does It Differ from Cast or Roller Chains?

A welded steel mill chain is a heavy-duty conveyor chain constructed from identical welded offset links. Two bent plates and a sleeve (without rollers) are welded together to form each link, and the pins articulate within the barrels of the links. This welded construction gives the chain exceptional impact resistance and tensile strength, making it ideal for the punishing conditions found in forestry, sawmills, pulp and paper mills, plywood plants, and bulk material handling operations.

Unlike cast chains, welded steel mill chains offer higher strength-to-weight ratios, better fatigue resistance, and more economical replacement costs. They are available in two construction series: WR series with heat-treated pins only, and WH series with all components (pins, barrels, and plates) fully heat-treated for maximum wear life and strength. The chain conforms to ASME B29.16M (Tooth Profile of Steel Welding Engineering Chains) and ISO 6972 (Cranked-link Mill Chains of Welded Construction).

Raydafon welded steel mill chains are supplied with a range of standard attachments and can be customized with special attachments for specific conveyor layouts. The chain is designed for low-speed, heavy-load applications with high impact, abrasive materials, and dusty environments — exactly the conditions where roller chains would fail prematurely.

Welded Steel Mill Chain with Attachment for Forestry and Bulk Material Conveying

Welded steel mill chain — welded offset link construction, WR/WH series, ASME B29.16M / ISO 6972 compliant

WR Series vs WH Series — What's the Difference?

The two construction series are distinguished by their heat treatment scope, which directly affects tensile strength, wear resistance, and service life. Selecting the right series depends on the severity of your operating conditions.

WR Series Heat-Treated Pins Only Only the pins receive heat treatment. Plates and barrels remain in their as-produced condition. Suitable for moderate-duty applications where abrasion is present but shock loading is not extreme. WR series offers an economical entry point for forestry and bulk handling. Heat treatment: pins only — tensile strength 93.4 kN (WR78) to 530 kN (WR150)

WH Series Fully Heat-Treated Components Pins, barrels, and plates are all heat-treated. This provides higher tensile strength, superior wear resistance, and longer service life in the most demanding applications — high shock loads, heavy abrasion, and continuous operation. WH series is the standard choice for pulp and paper mills, sawmills, and board plants. Heat treatment: all components — tensile strength 106.8 kN (WH78) to 820 kN (WH155)

For applications with extreme shock loads or heavy abrasion, consider WHXHD (extra heavy duty) variants with induction-hardened pins and barrels. Send your load and material conditions for a recommendation.

Technical Specifications — WR/WH Series Welded Steel Mill Chains

All welded steel mill chains are manufactured to ASME B29.16M and ISO 6972 standards. Chain links are processed by advanced welding equipment to ensure reliable weld quality and consistent pitch control.

Welded steel mill chain — key technical parameters
Parameter	Value
Chain Type	Welded steel-type mill chain (cranked-link, welded construction)
Standards	ASME B29.16M, ISO 6972
Series	WR (heat-treated pins), WH (fully heat-treated)
Available Chain Numbers	WR78, WH78, WR82, WH82, WR106, WH106, WR110, WH110, WR111, WH111, WR124, WH124, WR124H, WH124H, WR132, WH132, WR150, WH150, WR155, WH155, WR157, WH157
Pitch Range	66.27 mm (WR78/WH78) to 153.67 mm (WR150/WH150)
Min. Tensile Strength Range	93.4 kN (WR78) to 820 kN (WR155/WH155)
Average Tensile Strength Range	102.7 kN (WR78) to 902 kN (WR155/WH155)
Materials	Medium carbon steel, heat-treated; stainless steel available on request
Standard Attachments	A1, A2, A22, F2, F4, K1, K2, W1 and custom attachments
Sprocket Compatibility	ASME B29.16M / ISO 6972 sprockets with 5 to 36 teeth
Quality Standard	ISO 9001
Customization	OEM/ODM chain length, attachments, sprockets, packaging

Main Dimension Table — Welded Steel Mill Chain

The main dimension table below shows pitch, barrel diameter, plate depth, pin diameter, and tensile strength for all WR and WH series chain numbers.

Welded Steel Mill Chain Main Dimension Diagram — WR/WH Series — Main dimension diagram — chain number, pitch, barrel diameter, inner link width, pin diameter, plate depth and thickness references

Main dimensions and tensile strength — WR/WH series welded steel mill chain
Chain No.	Pitch P (mm)	Bush d1 (mm)	Inner Width b1 (mm)	Pin d2 (mm)	Pin L (mm)	Pin Lc (mm)	Plate h2 (mm)	Plate T (mm)	Tensile Q (kN/lbf)	Avg. Q0 (kN)	Weight q (kg/m)
WR78	66.27	22.90	28.40	12.78	73.00	79.3	28.4	6.4	93.4/21227	102.70	6.20
WH78	66.27	22.90	28.40	12.78	73.00	79.3	28.4	6.4	106.8/24273	117.50	6.20
WR82	78.10	31.50	31.80	14.35	80.00	86.0	31.8	6.4	100.1/22750	110.10	7.98
WH82	78.10	31.50	31.80	14.35	80.00	86.0	31.8	6.4	131.2/29818	144.30	7.98
WR106	152.40	37.10	41.20	19.13	103.00	111.0	38.1	9.7	169.0/38409	185.90	10.56
WH106	152.40	37.10	41.20	19.13	103.00	111.0	38.1	9.7	224.6/51045	247.00	10.56
WR110	152.40	32.00	46.70	19.13	107.70	115.5	38.1	9.7	169.0/38409	185.90	10.40
WH110	152.40	32.00	46.70	19.13	107.70	115.5	38.1	9.7	224.6/51045	247.00	10.40
WR111	120.90	37.10	57.20	19.13	116.80	124.5	38.1	9.7	169.0/38409	185.90	12.72
WH111	120.90	37.10	57.20	19.13	116.80	124.5	38.1	9.7	224.6/51045	247.00	12.72
WR124	101.60	37.10	41.20	19.13	103.00	110.0	38.1	9.7	169.0/38409	185.90	12.38
WH124	101.60	37.10	41.20	19.13	103.00	110.0	38.1	9.7	224.6/51045	247.00	12.38
WR124H	103.20	41.70	41.20	22.30	131.60	133.0	50.8	12.7	275.8/62682	303.30	19.68
WH124H	103.20	41.70	41.20	22.30	131.60	133.0	50.8	12.7	355.9/80886	391.40	19.68
WR132	153.67	44.70	76.20	25.48	151.00	162.2	50.8	12.7	275.8/62682	303.30	20.00
WH132	153.67	44.70	76.20	25.48	151.00	162.2	50.8	12.7	378.1/85932	415.90	20.00
WR150	153.67	44.45	73.00	25.40	151.00	162.2	63.5	12.7	530.0/119144	583.00	20.50
WH150	153.67	44.45	73.00	25.40	151.00	162.2	63.5	12.7	530.0/119144	583.00	20.50
WR155	153.67	44.45	73.00	28.57	164.00	176.0	63.5	12.7	820.0/186361	902.00	20.70
WH155	153.67	44.45	73.00	28.57	164.00	176.0	63.5	12.7	820.0/186361	902.00	20.70
WR157	153.67	44.45	76.20	28.57	164.00	176.0	63.5	15.9	820.0/186361	902.00	20.80
WH157	153.67	44.45	76.20	28.57	164.00	176.0	63.5	15.9	820.0/186361	902.00	20.80
WR78F5	66.27	21.30	20.00	12.70	62.99	66.1	25.4	6.4	66.7/14994	73.37	5.00
WH78F4	66.27	22.90	22.23	12.78	66.40	72.3	28.4	6.4	106.8/24009	117.48	5.94
WH124F1	101.60	31.75	38.10	19.05	101.50	109.5	38.1	9.5	253.0/56876	278.00	11.40
WH111F1	120.90	36.50	57.20	19.05	120.60	120.6	38.1	9.5	272.0/61148	299.20	12.63

Note: WR = welded steel chain with pins and bushes heat-treated only. WH = welded steel chain with all components fully heat-treated.

Standard Attachment Types — A1, A2, A22, F2, F4, K1, K2, W1

Welded steel mill chains are supplied with a full range of standard attachments for mounting scrapers, flights, buckets, and other conveying elements. These attachments are field-weldable for easy installation and replacement. ISO 6972 specifies eight standard attachment types for cranked-link mill chains.

A1 Single-side attachment for mounting scrapers and flights on one side of the chain

A2 Double-side attachment for simultaneous mounting on both sides

A22 Double-side attachment with extended projection for wider conveying elements

F2 Flat-top attachment for carrying flat plates or pans

F4 Wide flat-top attachment for large-area conveying surfaces

K1 Angle attachment for mounting flights at an angle

K2 Double angle attachment for angled flights on both sides

W1 Wing attachment for drag chain applications in bulk handling

Custom attachments can be developed to suit specific conveyor layouts. Send your drawing for engineering review.

Attachment Dimension Drawings — F2, F4, K1, K2, W1 and More

The following drawings show the dimensions for the standard welded steel mill chain attachment types. Each drawing is accompanied by its dimension table for engineering reference.

Drawing 2 — F-Series Attachment Dimensions (WR78/WH78, WR82/WH82)

F-Series Attachment Dimensions for Welded Steel Mill Chain — F-series attachment dimensions — h3, G, F, W, h4, d4, T references

Chain No.	h3 (mm)	G (mm)	F (mm)	W (mm)	h4 (mm)	d4 (mm)	T (mm)
WR78 / WH78	31.8	36.6	101.6	130.0	22.4	9.7	6.4
WR82 / WH82	38.1	46.0	106.7	142.7	23.9	9.7	6.4

Drawing 3 — Attachment Dimensions (WR78 to WH132)

Attachment Dimensions for Welded Steel Mill Chain WR78 to WH132 — Attachment dimensions — L, G, h3, F, W, h4, d4, T references

Chain No.	L (mm)	G (mm)	h3 (mm)	F (mm)	W (mm)	h4 (mm)	d4 (mm)	T (mm)
WR78 / WH78	28.4	52.3	38.9	101.6	130.0	22.4	9.7	6.4
WR82 / WH82	33.3	62.0	52.3	108.2	142.7	23.9	9.7	6.4
WR110 / WH110	44.4	84.1	98.6	135.1	168.1	30.0	9.7	9.7
WR111 / WH111	58.7	90.4	89.9	159.0	193.5	30.0	12.7	9.7
WR124 / WH124	49.3	77.7	71.4	133.6	180.8	30.0	9.7	9.7
WR124H / WH124H	49.3	80.8	73.2	133.6	165.6	39.6	12.7	12.7
WR132 / WH132	69.8	80.8	106.2	190.5	234.7	39.6	12.7	12.7

Drawing 4 — Attachment Dimensions (WR78/WH78)

Attachment Dimensions for WR78 WH78 Welded Steel Mill Chain — Attachment dimensions — h3, G, F, W, d4, T references

Chain No.	h3 (mm)	G (mm)	F (mm)	W (mm)	d4 (mm)	T (mm)
WR78 / WH78	33.3	30	47.8	65.0	9.7	9.7

Drawing 5 — Attachment Dimensions (WR78/WH78, WR82/WH82)

Attachment Dimensions for WR78 to WH82 Welded Steel Mill Chain — Attachment dimensions — h3, A, B, C, T references

Chain No.	h3 (mm)	A (mm)	B (mm)	C (mm)	T (mm)
WR78 / WH78	12.7	22.4	50.8	93.5	6.4
WR82 / WH82	15.7	28.4	57.2	93.5	6.4

Drawing 6 — Attachment Dimensions (WR78/WH78, WR82/WH82)

Attachment Dimensions WR78 to WH82 Welded Steel Mill Chain — Attachment dimensions — h3, A, C, T references

Chain No.	h3 (mm)	A (mm)	C (mm)	T (mm)
WR78 / WH78	7.9	20.8	93.5	6.4
WR82 / WH82	7.9	26.4	96.8	6.4

Drawing 7 — Attachment Dimensions (WR78/WH78)

Attachment Dimensions WR78 WH78 Welded Steel Mill Chain — Attachment dimensions — h3, h4, h5, F, W, d4, T references

Chain No.	h3 (mm)	h4 (mm)	h5 (mm)	F (mm)	W (mm)	d4 (mm)	T (mm)
WR78 / WH78	15.7	36.6	60.5	95.5	138.2	9.7	6.4

Drawing 8 — Attachment Dimensions (WR78 to WR124)

Attachment Dimensions WR78 to WR124 Welded Steel Mill Chain — Attachment dimensions — h3, h4, h5, L, C, F, W, d4, T references

Chain No.	h3 (mm)	h4 (mm)	h5 (mm)	L (mm)	C (mm)	F (mm)	W (mm)	d4 (mm)	T (mm)
WR78 / WH78	17.3	44.4	60.5	114.3	31.8	95.2	141.2	9.7	6.4
WR82 / WH82	20.6	46.2	62.0	127.0	28.4	104.6	150.9	9.7	6.4
WR124 / WH124	22.4	52.3	73.2	133.6	36.6	111.3	157.0	9.7	9.7

Drawing 9 — Attachment Dimensions (WR78 to WR124)

Chain No.	h3 (mm)	C (mm)	T (mm)
WR78 / WH78	17.3	41.1	6.4
WR82 / WH82	22.4	49.3	6.4
WR124 / WH124	31.8	49.3	9.7

Drawing 10 — Attachment Dimensions (WR78 to WR124)

Chain No.	h3 (mm)	C (mm)	T (mm)
WR78 / WH78	17.3	41.1	6.4
WR82 / WH82	22.4	49.3	6.4
WR124 / WH124	31.8	49.3	9.7

Drawing 11 & 12 — Attachment Dimensions (WR78 to WH132)

Attachment Dimensions WR78 to WH124H Welded Steel Mill Chain — Attachment dimensions — h3, W, T references

Attachment Dimensions WR78 to WH132 Welded Steel Mill Chain — Attachment dimensions — h3, W, T references

Chain No.	h3 (mm)	W (mm)	T (mm)
WR78 / WH78	19.1	153.9	6.4
WR82 / WH82	23.9	166.6	6.4
WR124 / WH124	30.0	217.4	6.4
WR124H / WH124H	35.1	217.4	9.7
WR132 / WH132	38.1	316.0	9.7

Drawing 13 — Special Attachment Dimensions (WH78F10, WH82F3K2, WH150F2)

Attachment Dimensions WH78F10 WH82F3K2 WH150F2 Welded Steel Mill Chain — Special attachment dimensions — WH78F10, WH82F3K2, WH150F2

Chain No.	h3 (mm)	F (mm)	L (mm)	W (mm)	d4 (mm)	T (mm)
WH78F10	12.0	—	—	—	—	6.4
WH82F3K2	30.0	128.0	34.0	260.0	11.0	10.0
WH150F2	72.0	230.0	70.0	430.0	14.0	10.0

Drawing 14 — Special Attachment Dimensions (WH78F6)

Attachment Dimensions WH78F6 Welded Steel Mill Chain — Special attachment dimensions — WH78F6

Chain No.	h3 (mm)	h4 (mm)	h5 (mm)	G (mm)	L (mm)	d4 (mm)	T (mm)
WH78F6	15.7	36.6	60.5	75.0	55.0	6.7	6.4

Product Views & Attachment Configurations

Product views show the welded offset link construction and standard attachment configurations.

Welded Steel Mill Chain Product View — WR/WH Series Construction

Welded offset link construction detail — bent plates, barrel and pin assembly without rollers

Welded Steel Mill Chain with Attachment — Standard Configuration

Welded steel mill chain with standard attachment — A1, A2, F2, F4, K1, K2, W1 configurations

Typical Applications — Forestry, Sawmills, Pulp & Paper, Bulk Material Handling

Welded steel mill chains are engineered for the most demanding conveying environments. They are the backbone of operations where cast or roller chains would fail under the combined stresses of shock loading, abrasion, and dust.

Forestry & Sawmills Log hauling, chip conveying, sawdust handling, and waste wood transport. The welded construction absorbs the shock loads of log drops and uneven feeding.

Pulp & Paper Mills Conveying of wood chips, bark, ash, and other bulk materials through the pulping and papermaking process. WH series is standard for these high-abrasion environments.

Plywood & Board Mills Panel handling, trim waste conveying, and sander dust collection. The flat-top and angle attachments are widely used in board handling systems.

Bulk Material Handling Bucket elevators, drag conveyors, and feeders for cement, aggregate, fertilizer, and grain. The chain withstands high dust and impact conditions.

Ash & Refuse Handling Bottom ash conveyors, refuse-derived fuel systems, and boiler feed systems. The welded links resist the combined effects of heat, abrasion, and corrosion.

Steel & Foundry Scrap handling, slag conveying, and sand reclamation. Heavy-duty WHXHD variants are specified for extreme shock loading and high temperatures.

How to Select the Right Welded Steel Mill Chain — 6-Step Guide

STEP 1 Identify the conveyed material and operating conditions Wood chips, sawdust, ash, and refuse are highly abrasive and dusty. Determine the maximum material size, density, and temperature.
STEP 2 Calculate the required working load and tensile strength Determine the maximum chain tension from the conveyor layout, material weight, and incline. Apply a service factor of at least 4 to 6 for shock-loaded applications to determine the minimum required tensile strength.
STEP 3 Choose WR or WH series WR series for moderate abrasion and normal shock loads; WH series for high abrasion, heavy shock, and continuous operation. WHXHD for extreme conditions.
STEP 4 Select the chain number and pitch Chain numbers range from WR78/WH78 (66.27mm pitch) to WR150/WH150 (153.67mm pitch). Larger pitch handles larger material and higher loads.
STEP 5 Specify the attachment type Choose from A1, A2, A22, F2, F4, K1, K2, W1, or custom attachments based on the conveying element (scraper, flight, bucket, pan).
STEP 6 Confirm quantity and delivery Provide chain number, attachment type, required length (in pitches or meters), quantity, destination port, and whether OEM branding or custom packaging is needed.

Why Choose Raydafon Welded Steel Mill Chains?

Advanced Welding Process Chain links are processed by advanced, efficient welding equipment to ensure reliable welding quality and consistent pitch control. The welded construction provides higher strength-to-weight ratio than cast chains and better fatigue resistance in high-cycle applications.

ASME B29.16M & ISO 6972 Compliant All chains are designed and manufactured in accordance with ASME B29.16M and ISO 6972. Dimensions ensure interchangeability of both complete chains and individual links for repair purposes. Sprockets with 5 to 36 teeth are available.

WR and WH Series Available WR series (heat-treated pins only) offers an economical solution for moderate-duty applications. WH series (fully heat-treated) delivers maximum tensile strength and wear life for the most demanding forestry and bulk handling operations.

Full Range of Attachments Standard attachments include A1, A2, A22, F2, F4, K1, K2, and W1. All attachments are field-weldable for easy installation. Custom attachments can be developed to suit specific conveyor layouts. Send your drawing for engineering review.

Ordering & Supply Information

What to send for a fast quotation

Chain number (e.g., WR78, WH106, WR124, WH150)
Series preference (WR or WH)
Required chain length (in pitches or meters)
Attachment type (A1, A2, A22, F2, F4, K1, K2, W1, or custom)
Quantity and destination port
OEM branding or custom packaging requirements

Supply terms

Sample and trial orders accepted for fitment verification
MOQ depends on stock status — confirm per order
Export packing: wooden case or pallet
Material certificates and dimensional inspection reports available
Matching sprockets available on request
Lead time: 7–15 days for samples, 25–35 days for mass production

Frequently Asked Questions

What is a welded steel mill chain and how does it differ from cast or roller chains?

A welded steel mill chain is constructed from identical welded offset links. Two bent plates and a sleeve (without rollers) are welded together to form each link, and pins articulate within the barrels. Compared to cast chains, welded steel chains offer higher strength-to-weight ratios, better fatigue resistance, and more economical replacement costs. Compared to roller chains, they provide superior impact resistance and are better suited for abrasive, dusty, and high-shock environments. They are the standard choice for forestry, sawmills, and bulk material handling.

What is the difference between WR series and WH series?

WR series has heat-treated pins only, while plates and barrels remain in their as-produced condition. WH series has all components — pins, barrels, and plates — fully heat-treated, providing higher tensile strength, superior wear resistance, and longer service life. WR series is suitable for moderate-duty applications; WH series is standard for high-abrasion and heavy shock loading conditions such as pulp and paper mills and sawmills. WHXHD (extra heavy duty) variants are available for extreme conditions.

What attachment types are available?

Standard attachments include A1 (single-side), A2 (double-side), A22 (double-side extended), F2 (flat-top), F4 (wide flat-top), K1 (angle), K2 (double angle), and W1 (wing). These attachments are field-weldable for easy installation and are used for mounting scrapers, flights, buckets, and pans. Custom attachments can be developed to suit specific conveyor layouts.

What materials and coatings are available?

Standard material is medium carbon steel with heat treatment (WR series: pins only; WH series: all components). Stainless steel is available on request for corrosive environments. Surface treatments including induction hardening and special coatings can be specified for enhanced wear resistance.

How do I select the right welded steel mill chain for my application?

Determine the conveyed material, maximum chain tension, and operating conditions. Apply a service factor of at least 4 to 6 for shock-loaded applications. Select WR series for moderate duty or WH series for high abrasion and heavy shock. Choose the chain number based on pitch and load requirements. Specify the attachment type based on the conveying element. Provide chain number, attachment type, length, and quantity for a confirmed quotation.

Get Your Welded Steel Mill Chain Quote

Send chain number, series, attachment type, length and quantity — our engineers confirm the correct configuration and return a quotation within 24 working hours.

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