Through hardened boron is now universally accepted as the ideal grade to use in agricultural components with just a small addition of boron to a standard carbon steel, it allows the perfect balance of :
- Maximum toughness for the ultimate wear resistance against abrasion
- Minimal risk of fracture in tough stony field conditions
At Chapmans, after considerable research and development which was part funded by G T Bunning, unique equipment has been designed and developed to make the complex bending of an auger section during the heating process of heat treatment. This means that no auger section has any inherent residual stresses in the steel from the production process, reducing the risk of breakage but dramatically increasing the life of the auger assembly.
The heat treatment process, at temperatures of up to 980 deg C ensures that all auger sections are consistently hard at up to levels of 52 HRC which lowers the chances of augur deformation during the working life of an auger. Previously, auger sections were unhardened and formed from a cold forming process which meant softer auger sections, liable to deformation and cracking and ultimately, breakage. Auger shape is now very consistent giving a more consistent spreading pattern in the field.
Auger sections have a slightly softer centre than the outside, which allows more flexing of the assembly during rotation whilst the outside of the auger is harder to ensure toughness and rigidity. Following extensive field trials and testing criteria examinations, G T Bunning have signed an Agreement with Chapmans which gives Bunning exclusive access and rights to these major advances in ‘Through Hardened Boron Auger Technology’.
Even the spreader tips are now produced from heat treated boron, to ensure the auger points have enhanced wear life to match the augers, with a design permitting the tip to be reversed after wear at either end.