Sharp cutting edge – big impact
When removing feed from the silo, an inconspicuous detail often determines clean working, low wear and safety in the feed ration: the cutting edge on the shear bucket and shear grabs. Whether this is a screw-on cutting edge or a welded cutting edge makes a significant difference in everyday use.
At Agritechnica, a large number of farmers told us that they had to regularly replace the screw-on cutting edge on their shear grabs – because the screw-on cutting edge was increasingly becoming blunt. In addition, there is always the concern: what happens if broken blades or cutting edge parts end up in the feed ration?
This is exactly where MAMMUT’s approach comes in. The shear buckets and shear grabs feature a welded Hardox cutting edge that has been specially developed for daily feed removal. Yes, every cutting edge is a wearing part – but it does not have to be designed in such a way that it needs to be replaced.
This article shows
- the differences between bolted and welded cutting edges
- and which of the two solutions is low-maintenance, energy-saving and safe for feed presentation in everyday use.
Two basic designs have established themselves on the market: the bolted cutting edge and the welded cutting edge. In the case of the bolted cutting edge, the cutting edge is fastened with bolts and is considered a classic wear part from the outset. The welded cutting edge is firmly connected to the device and designed for high loads in daily use.
MAMMUT deliberately uses a welded cutting edge made of Hardox in its extraction devices – for several reasons.
Comparison: bolt-on cutting edge vs. welded Hardox cutting edge
Design requirement as an additional weak point
In many bolt-on cutting edges, the cutting edge is mounted on a shear grab or shear bucket with countersunk screws so that the screw heads themselves do not protrude into the silage. However, in order for the cutting edge to be attached, the extraction device is designed so that a strip of material protrudes, on which the cutting edge rests. When penetrating the silage, this protruding material forms an edge that acts like a step in the feed, increasing resistance and mechanical stress. In practice, the area around this support and the fastening is often the first to wear out, especially with intensively used equipment such as shear grab and shear bucket.
Moisture and fermentation juices prevail in the silo. These penetrate the spaces around screw heads and drill holes. Acids and salts attack the metal parts, and screws and nuts begin to rust. What was supposed to be a simple cutting blade change then becomes a time-consuming task. What was intended to be a ‘flexible system’ thus becomes a regular source of annoyance for many businesses.
Smooth, welded Hardox cutting edge with fewer points of attack
The situation is different with the welded Hardox cutting edge. The cutting edge sits directly under the cutting basket and forms a smooth, continuous edge without any protruding material. This means there is no unnecessary loss of power and the cutting edge glides through the feed without any interference. In addition, the resistance-free gliding through the feed stock results in an even cutting edge in the mobile silo. This protects not only the removal device but also the grass silage and maize silage.
There are no drill holes in which fermentation juices can collect. Wear occurs where it should: evenly along the cutting edge.
Hardox is a heavy-duty wear-resistant steel designed for tough applications. In combination with the welded design, this creates a cutting edge that can withstand daily removal.
Safety in feed rations: broken cutting parts in the feed
Risk of foreign objects in feed
Foreign objects in feed rations are a particularly sensitive issue. With bolted cutting edges, locally overloaded areas at drill holes or in the bolt area can lead to cracks and breakage. Broken knife tips or cutting parts can remain in the silo stock, be removed later and ultimately end up in the feed trough. In extreme cases, this can lead to injury or death of animals.
Stable, welded Hardox cutting edge contributes to safety
The stable, continuous welded cutting edge made of Hardox significantly reduces this risk. There are no areas in the cutting area that are weakened by drill holes, the breakage resistance is high due to the solid, continuous steel, and wear is uniform without localised overload. The more stable the cutting edge is constructed, the lower the probability that parts will break off and end up in the feed ration.
Robust welded cutting edge prevents material breakage
Guaranteed feed quality without the worry of foreign bodies from the cutting process
Vital and healthy livestock will be provided with optimal feed
Force flow during the cutting process: clean cut instead of blockage
During the cutting process, the force of the carrier vehicle should be transferred as evenly as possible into the silage stock. With screw blades that are fastened with countersunk screws, there are no screw heads protruding, but the protruding strip of material required for fastening forms a structural edge. When penetrating the silage, this edge acts like a step on which the pressure is concentrated at specific points instead of being distributed evenly across the entire cutting edge. This results in localised stress, requiring more hydraulic pressure and sensitivity, and increasing the amount of force required – resulting in higher wear and tear and less comfort in daily work.
The continuously welded Hardox cutting edge on the shear bucket and shear grab, on the other hand, ensures a significantly smoother force curve. The pressure is distributed across the entire cutting edge, the cutting edge penetrates the feed evenly and cuts the block cleanly, cutting the silage stock instead of tearing it. This protects the silage stock, as less air penetrates and the silage quality is maintained, reduces the traction required by the carrier vehicle and relieves the driver thanks to smoother operation.
Low maintenance in everyday use thanks to welded Hardox cutting edge
Even a Hardox cutting edge is subject to wear – but significantly less so. After prolonged use, the cutting edge can be resharpened with an angle grinder with a flap disc. The cutting effect is maintained without having to replace any components. This work is quick and much less time-consuming than a complete blade replacement with several screws.
In the rare cases where it is necessary to replace the cutting edge, the cause is usually not normal wear and tear, but rather large foreign objects in the silo – such as stones or metal parts that have been stored unnoticed and cause severe damage to the cutting edge. In these exceptional cases, the procedure is clearly defined: the old cutting edge is cleanly cut off and a new Hardox cutting edge is welded on. This procedure is limited to special cases and is not intended as a regular maintenance measure.
‘When you compare our old silo cutting tongs with the MAMMUT silo cutting tongs, I particularly notice that the welded cutting edge glides very easily through the silage to be removed with very little effort in daily use.’
– Henryk Schultz, Agrargenossenschaft Oberes Elbtal Reinhardtsdorf e.G.
Who benefits from shear buckets and shear grabs with a welded cutting edge?
At the end of the day, what counts is what happens in everyday use: clean removal, safe handling of the feed and as little effort as possible for wear and maintenance. A shear bucket or shear grab with a welded cutting edge made of Hardox is particularly interesting for farms that
that remove silage on a daily basis,
that value a smooth, energy-saving way of working,
that want to spend as little time as possible changing blades and dealing with rusted bolts,
that want to minimise the risk of foreign objects in the feed ration
and that want a smooth cut and to avoid unnecessary quality losses in the feed.
The combination of a smooth, welded Hardox cutting edge, optimised power flow and low-maintenance design makes this system a robust solution for modern feed removal.
If you want to check whether this cutting system is suitable for your silo situation, operating procedures and existing carrier vehicle, take a closer look at MAMMUT extraction technology – cutting shovels and shear grabs with welded Hardox cutting edge. The MAMMUT team will be happy to discuss an individual solution for your business.
