Boxholm Stål AB can provide different services and processes for refining bars.

 

 

 

Boxholm Stål AB supplies bars whose mechanical properties have been tested in different ways. Tests are performed using both our own equipment as well as our next-door neighbour Ovako.

 

These tests include the testing of yield point and tensile strength, impact toughness, hardness and elongation.

 

Boxholm Stål AB's bars undergo crack detection tests, eddy-current testing. The equipment consists of a Circograph Ro65 – 4 test probes rotating at 3000 rpm during testing of round material, a Defectomat M170 with surrounding spools which is used for testing hexagonal bars. Bars are evaluated with a Circograph, after which they are demagnetised.

 

The range of available dimensions is 6-65 mm for round bars and 6-55 mm for hexagonal bars.

 

Each test is documented in a test report.

 

 

Precision cutting can be performed using a number of different machines:

A circular saw, three band-saws and one high-speed cutting machine.

 

 

End chamfering of one or two ends – without or without facing – drilling of spike holes and turning of handles.

 

 

Boxholm Stål AB supplies special/double-straightened bars, which means that with round bars, the machine operator tries to achieve a maximum straightness deviation of 0.25 mm/m. This is achieved by carefully setting the straightening machine or by straightening the material twice.

 

 

Boxholm Stål AB supplies heat-treated bars, either from our own annealing furnace or our next-door neighbour Ovako.

 

The heat treatment methods we use are annealing and normalising.

 

Tolerances for heat treatment below 720˚C is h11. Above 900˚C it is h12 or higher.

 

 

Boxholm Stål AB supplies bars that have undergone ultrasonic testing. Tests are performed manually and the material is tested on 3 sides (10 00, 14 00 and 18 00).

 

An acceptance level of FBH Ø 2 mm is implemented for cold-drawn bars. In other words, discontinuities that give a flow echo larger than the echo from a 2 mm-diameter flat-bottom hole are discarded.

 

 

 

Boxholm Stål AB supplies bars that are marked, which simplifies the process of identifying and tracking the bar during the manufacturing process.