This section of the Abba web site is intended to furnish you, the buyer, with an understanding of the steels used within the tipper industry and more widely in the construction sector.

All steel tipping bodies are produced using one of two basic types of steel, 'Strip Mill' or 'Reversing Mill' plate.

Strip Mill

Background

Strip Mill is steel produced using a hot rolling process. The steel is passed through numerous sets of rolls until the required thickness is achieved. The steel is tested to a given tensile strength, certificated and then released from the Strip Mill in the form of a coil. The coil would generally be either 1m, 1.25m 1.5m, 1.83m or 2m wide.

This type of material is usually known as grade 43 or 50. It is the basic mild steel, produced and used for everyday purposes all over the world. It will be "de-coiled" either at the distributor or by a local specialist, either into standard sizes such as 2.5 x 1.25m, or into specific lengths to suit a given product. Thus, to suit the length of an eight wheel tipper for example, many tipping body manufactures will have their Strip Mill material de-coiled at 6.7m.

This type of material is the cheapest steel available and is suitable for use in the sides of double skinned bodies, as the distortion suffered by the inner skin does not show on the exterior. Therefore, where a manufacturer chooses to utilise a higher specification of steel, it will inevitably be more expensive. In this way, some tipping body manufacturers will not release the specification of steel they use for bodies, as the increased cost may deter customers.

Use of Strip Mill Steel at Abba

There are specialist types of Strip Mill material available, which offer a higher tensile strength than grade 43 – 50 material. At Abba we use a material called Domex, which is manufactured by Swedish Steel. Domex 690 has a tensile strength higher than grade 50 steel. We incorporate Domex into areas of the bodywork where weight saving is important, but not into areas where which will come into contact with the load on a day to day basis. Whilst Domex is of a much higher tensile strength than mild steel, it may still distort in the severe impact environment encountered by tipping bodies in the construction sector. In these situations, the manufacturer may choose to use reversing mill steel. (See below).

Reversing Mill

Background

The strip-mill process cannot produce stronger steels in the widths required for the tipping bodies of today. The system required to produce harder steels or "wear plate" is known as the "Reversing Mill" process. Effectively each plate is produced individually, with the material passing backwards and forwards through the rolls, until the required specification is met. Wear plate is measured for its hardness using an impact test and classified for it’s "Brinell hardness". (See also appendix A)

Use of Reversing Mill Steel at Abba

There are numerous manufacturers of Brinell hardness material, however at Abba we use the best known and in our opinion, the best quality Brinell material: Hardox. We have settled on the 450 grade as the most suitable for our bodies. The reverse rolling technique is time consuming and thus the plate is more expensive.

The Predator body has the highest content of Brinell 450 material available from any UK body builder, and thus Predator will never be a cheap body. However, as a rule of thumb Brinell 450 material is two and a half times as strong as the mild steel outlined at the beginning of this article. This can lead to lower overall tipper weight and increased load capacity as well as a body better able to withstand heavy daily use.

Appendix A:

If a body builder claims that a body is made from Hardox there are some very simple methods of checking the validity of this:

• Hardox and the grade are written on every plate, which can normally be seen on the inside of a body.
• Confirm with SSAB, we have a link to their website below. Hardox is supplied to very few UK body builders and a certification process exists.
• Try and drill a hole in it! A normal high speed steel drill bit will burn out long before it makes a hole in the Hardox.
• Buy one and put concrete in it. We were once shown a body which was supposed to have had a Hardox floor. The reinforcing bar had gone straight through!
• Finally, it is worthwhile to check which components are made from Hardox, as most body builders use Hardox in the floor only.

Visit the SSAB website >>

The difference in price between 'Grade 50 Material' and 'Brinell 450' can be up to £1000 per tonne!