ASME B29.300-2015 — Agricultural, Detachable, and Pintle Chains, Attachments, and Sprockets

🌾 ASME B29.300-2015 is the American National Standard that consolidates three families of agricultural-type chains into a single document: B29.6 steel detachable link chains, B29.19 agricultural roller chains, and B29.25 open barrel steel pintle-type conveyor chains, together with their attachments and sprockets. On August 2, 1998, the B29 Standards Committee agreed via letter ballot to consolidate and revise these three standards, integrating the agricultural-type chains found in each. The 1998 editions unified symbols and sprocket information throughout the consolidated B29.300 standard and made the sprocket tooth form identical for all three chains. The 2015 revision adds new chains now common in the agricultural industry and was approved as an American Standard on November 23, 2015. The body is organized by chain family: Part 1 B29.6 steel detachable link chains, Part 2 B29.19 agricultural roller chains, and Part 3 B29.25 open barrel steel pintle-type conveyor chains.

1. B29.6 Steel Detachable Link Chains 🔗

Detachable link power transmission chains have been used almost exclusively by agricultural implement manufacturers for power transmission and conveyors on manure spreaders, corn pickers, planters, hay rakes, potato diggers, elevators, and many other machines. The first steel detachable link chain was manufactured in 1897 from special analysis steel strip, heat treated after forming for wear resistance, strength, and toughness. A defining feature is that links can be detached by hand for fast assembly and repair.

• Dimension system: graded by pitch and link plate width; the 1960 revision deleted low-popularity sizes closely similar to existing ones and added popular chains, attachments, and couplers.
• Coupler and coupler pin: revised to the currently more popular style, allowing any link to be used right- or left-handed.
• 1994 update: deleted Numbers 45 and 67, which are no longer manufactured, and updated the definition of Minimum Ultimate Tensile Strength (M.U.T.S.).

2. B29.19 Agricultural Roller Chains ⚙️

Agricultural replacement roller chains, introduced around 1956, give implement engineers an upgrade from cast or steel detachable chains: higher strength and durability, usable with the same sprockets. They are available in:

CA550 and CA620 may be used on No. 55 and No. 62 detachable chain sprockets respectively; however, because of the difference in roller diameters, the sprocket data in the Standard is for sprockets designed specifically for CA550/CA620 chains. The 1993 revision updated the format and symbols; 1996 renamed the Standard and added chains and attachments; 1998 unified the sprocket tooth form.

3. B29.25 Open Barrel Steel Pintle Conveyor Chains 🧷

The open barrel steel pintle chain was originally developed in 1962 for the agricultural implement industry; original sizes were designed to run on the same sprockets as their detachable chain counterparts, and later sizes accommodate industrial applications as well. It is primarily a conveyor chain and, in limited use, a power transmission chain; typical conveyor speeds are under 300 ft/min — consult manufacturers for details.

• Construction: pin links alternate with open-barrel links whose open sides allow dirt to shed during operation.
• Size expansion: the 1994 revision restated the M.U.T.S. definition and added footnotes on attachment hole sizes; 1998 combined Tables 1 and 2 and unified the tooth form; this edition adds two new pintle chains, 88C and 308C.

4. Attachments 🔩

Tables 2 through 6 give the principal attachment dimensions:

• C11E, C13E, C6E attachments: bent-plate/wing types for scrapers and pushers.
• C17E attachment: a dedicated bent-plate form.
• A19 attachment: straight plate with holes for buckets and cross beams.
• F14 attachment: wing plate for lateral load carrying.
• K39M attachment: bent-foot type for a range of implement interfaces.

5. Sprockets and Interchangeability ⚙️

The Standard unifies the sprocket tooth-form symbol system for all three chains, and the sprocket sections give pitch diameter, tooth-form elements, tooth-count ranges, and maximum hub diameters. On interchangeability, the Standard mainly establishes the dimensions that provide for interchangeability of chains in use without restricting manufacturers’ overall designs. The relationship between agricultural roller chain and detachable chain sprockets is explained in Section 2.

6. Engineering Practice Essentials 🛠️

• Selection: prefer agricultural roller chain for power transmission (higher strength and durability); detachable chain for low-cost conveying; open barrel pintle chain for dusty, heavy-duty, long conveying runs.
• Speed limits: pintle conveyor speeds are generally below 300 ft/min; above that, consult the manufacturer or switch to roller chain.
• Tension and alignment: all three families require controlled slack-side sag and sprocket face alignment; pintle and detachable chains especially need protection from edge wear and disengagement.
• Maintenance: periodically check pitch elongation, attachment bolts, coupler condition, and sprocket tooth wear.

7. Frequently Asked Questions ❓