AGRICULTURAL CHAIN & ASSEMBLIES
Flail Chains
Flail chains for side discharge muck spreaders are subject to heavy wear. Experience has resulted in most machine manufacturers adopting a very similar specification for their chains. Apart from wear resistance the chains must be ductile enough not to shatter in service.
Case hardening gives the steel an extremely hard "skin" whilst leaving the inner core comparatively soft. It is important to have the right proportions between case and core to achieve maximum life without the possibility of brittleness. Machines when new normally have 40 to 50mm clearance between flail heads and the drum. As chain wears it appears to stretch. What is actually happening is that wear is taking place where the links rub together, and this causes a lengthening of the chain. For example, a 15-link chain has 30 points of wear, and 1mm of wear results in a 30mm increase in chain length.
The following table lists standard flail chain assemblies which fit most machine makes. Select a length which gives the appropriate clearance to the drum. Chains are fitted to heads by double roll pins, one inside the other. This is a well-proven system enabling easy replacement of worn parts. Heads are not case hardened and extension plates are available if required.
| Description | Overall length approx. | Description | Overall length approx. |
| 3/8" x 13 link chain only | 430mm | 3/8" x 13 link chain c/w head | 455mm |
| 3/8" x 15 link chain only | 520mm | 3/8" x 15 link chain c/w head | 545mm |
| 3/8" x 19 link chain only | 625mm | 3/8" x 19 link chain c/w head | 650mm |
| 1/2" x 12 link chain only | 500mm | 1/2" x 12 link chain c/w head | 525mm |
| 1/2" x 13 link chain only | 540mm | 1/2" x 13 link chain c/w head | 565mm |
| 1/2" x 14 link chain only | 585mm | 1/2" x 14 link chain c/w head | 610mm |
| 1/2" x 15 link chain only | 620mm | 1/2" x 15 link chain c/w head | 645mm |
Towing Chains
Towing chains are versatile and useful pieces of equipment on a farm, but need
to be handled with care. They should not be used for lifting purposes. We offer a range of sling chains specifically designed for lifting, and meeting the requirements of British and International Standards.
A towing application is highly likely to impose shock loads, and these will frequently result in breakage. Consequently our towing chains tend to be somewhat more ductile than our slinging equipment and with a greater capacity to absorb shocks. In spite of this, snatch loads should be avoided as much as possible. The load should be applied in a steady and even manner and chains should be free from knots or twists.
A further difficulty is that it is impossible to estimate the forces applied to a chain in a towing application. Are we pulling a trailer along a flat tarmac road or is it on its side and stuck in a ditch? Will the driver be tempted to rev up and have a run at it? There is no easy answer, but experience suggests that a chain with a test load equal to the trailer weight is usually adequate. All our towing chains are tested and supplied with a test certificate.
| Chain diameter | 9.5mm | 12mm | 16mm | 19mm |
| Proof test load | 1.82t | 2.8t | 5.0t | 7.2t |
Making Chain Connections
Ideally chains and components should be assembled by the original manufacturer. In reality this may be impractical, and a variety of mechanical connectors have evolved, some more effective than others. For general purposes we consider mild steel shackles or rapid links to be good value.
Shackles
There are many varieties of shackles, in different strengths and with different types of pins. Some are designed for specific applications whereas others are for general use. The types shown are known as commercial pattern with screwed collared pins, either "dees" or "bows". They are inexpensive and well suited to the majority of farming applications.
When the intention is to use them with chain, bear in mind that short link type chain has very limited admittance in a link. Even the last link of a short link chain will not accept the eye of an adequately sized shackle, although it will accept the pin. Shackles are more useable with long link type chain, and this is probably the best combination for the farmer.
Commercial pattern shackles are cheap enough for the farm to carry a selection in stock, and we are always pleased to advise on the dimensional compatibility between shackles and chain – or, indeed, any of our products.
Rapid Links
Rapid (or "quick") links have become popular in recent years. Although weaker than a chain of equivalent diameter they will work with most chains and components easily, and are very simple to use. An extremely versatile product which finds a multitude of uses.
Loadbinds and Loadbinder Chain
Proven over many years this tool is used for lashing and securing in a wide range of industries. Loadbinders are available in different sizes for different chain diameters, 9.5mm being the most popular. The different design based on the ratchet principle is also available.
For a lashing application a chain needs to have a combination of strength and shock resistance, and we recommend our "grade 40" short link type. This particular quality is up to double the strength of some mild steel chains and is metallurgically stabilised against brittleness.
Calibrated Chains
Chains driven by pocketed wheels are very common in the farming industry. Such chains need to be accurately dimensioned and consistent to run smoothly. This accuracy is achieved by "calibrating", a process whereby a chain is deliberately manufactured with shorter links than are required and is then physically stretched to its final dimensions. It is all too often assumed that if a wheel works with a 10mm chain, for example, then just specifying a 10mm calibrated chain will ensure a suitable replacement. This is not the case.
Machine manufacturers frequently use chains of different dimensions to those their competitors use. This may be simply to keep a captive market for spares, or for strictly practical reasons. One manufacturer of a machine where the chain is prone to severe wear offers a number of slightly different wheels. As the chain wears and lengthens the user can replace wheels with ones which are a better fit to the worn chain and thus achieve a much longer working life.
It is essential that any requirement for chain to fit a wheel should be as fully specified as possible. Even then, the supplier may need the loan of the wheel in question to ensure compatibility.
Traditionally our market in the agricultural industry has been the machinery manufacturers, and many of the famous names remain good friends and valued customers. The reducing UK manufacturing base has coincided with an upsurge in "spurious spares", however, many imported from the cheapest sources and of dubious quality. You will have already realised that although all chain may look alike it can vary enormously in its properties. Strength, hardness, ductility, etc. are all "tuned" to give optimum characteristics for the application. Best results can only be achieved through a knowledge of the product which a trader rarely possesses.
OTHER PRODUCTS FOR AGRICULTURE INCLUDE
| • Wear resistant chains for slurry scraper systems • High performance bolt cutter resistant security chains • Hitch chains • Adjusting screws • Sling chains • Lashing chains |
• High strength chains for rear discharge machines • Feed conveyor chains for poultry systems • Eyebolts and eyenuts • Couplings |
Our Blacksmith's Shop
In our factory we still have the original building where our business started over a century ago. Then it was chainmakers working on open fires with hammers and anvils. Now the building is bigger, cleaner, in all ways better to work in and it contains a wide variety of modern metalworking machinery. We still have a blacksmiths' hearth and some of the work is still done with hammer and anvil!
Our modern version of a Smithy combines traditional skills with electric resistance heaters, hydraulic benders and presses, flash butt welding and general fabrication facilities.
We make ring bolts, ragged bolts, dees, triangles, rectangles. Keyhole, banana and heart-shaped links. Welded fabrications, hand, press and hammer forgings. We re-shape and repair all manner of metalwork. Our Smithy combines with our machine shop to produce an amazing range of products in any quantity from one to a thousand!
If you have an unusual requirement please send your drawings to our sales office and we will try to supply your needs.
Email sales@bradneychain.co.uk or fax them to 01384 634289
