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1. What is machining?

Machining is the process of using a machine tool to cut, shape or remove material from a workpiece by cutting off chips. Machining is called subtractive manufacturing, in contrast to additive manufacturing (3D printing). 

2. What are the various machining operations?

The three main machining operations are drilling, milling and turning. 






3. Is it possible to machine high-strength steels?

Yes, provided the operator has been properly educated and the machine is stable enough to run safely with carbide insert tools of good quality.

4. What is CNC machining?

Computer Numerical Control (CNC) uses a computer program to control the sequence of operations of the machine. 

5. Where can I find cutting data for machining SSAB steel?

Cutting data for machining is available in SSAB’s machining brochures.

6. What is material hardness?

Material hardness is the ability to resist indentations by the pressure of other objects. 

7. What is machinability?

The term machinability refers to the ease with which a material can be machined to give a satisfactory result, including the machined surface, tool life and costs.  

8. How does material hardness affect machinability?

A harder steel will shorten tool lifetime. A lower cutting speed will do the opposite.

9. Can I use a column or radial drilling machine when drilling into wear plates?

You can use a column or radial drilling machine for very hard steel, like wear plates, provided the drilling machine is stable and robust enough, and sufficiently powerful.

10. What is drilling?

Drilling is a chip-forming machining method where a bit or insert with a cutting edge mounted on a rotating spindle is forced into a workpiece, to create a round hole. In most cases the workpiece is clamped, and the drill rotates but the opposite arrangement is also possible.

11. Can I use a high-speed steel drill to drill into wear plates?

It is possible to drill into very hard steel, like wear plates. For Hardox grades up to Hardox 500, you can drill single holes into a stationary drilling machine with high-speed steel drill/you can use a stationary drilling machine with a high-speed drill to drill single holes together with low cutting speed and a lot of cooling. For even harder steels, a solid carbide drill or a carbide tipped drill must be used. 

12. Can I use a hand drilling machine when drilling into wear plates?

It is not recommended to use hand drilling machines when drilling in hardened steels.  A human operator using a hand-held machine are not very stable and do not have the power necessary to get a satisfactory result.

13. How can I drill with indexable inserts into hardened steel?

To increase stability, use as short a drill as possible. The center insert will take more punishment, so choose a softer insert, while a harder peripheral insert is recommended where the wear is higher.

14. How do I use a coated solid carbide drill for wear plates?

When used in a stable and powerful machine with good clamping facilities, a solid carbide drill is the optimum choice for drilling into all Hardox® wear plate grades.

15. How can I countersink pre-drilled holes?

Use countersinking tools with carbide inserts in a stable machine. SSAB has recommendations on tools and suppliers.

16. How can I countersink if not using an appropriate countersinking tool?

If you have access to a CNC machine, you can spiral interpolate the shape of the chamfer with a solid carbide end mill. However, this approach takes much longer and becomes more expensive. See question number 15 for appropriate countersinking tools. 

17. What is milling?

Milling is a cutting process producing chips. Cutting inserts are rigidly mounted on a rotating tool (milling body). The milling body cutting edges can have various shapes. The workpiece is clamped onto a table. Both the table and the tool can be moved independently in one or more spatial dimensions. The movements can be controlled manually or by a computer program (CNC). 

18. How can I mill wear plates?

The machine must be stable, and the workpiece must be well clamped. Use only a milling body equipped with carbide inserts for wear plates harder than 400 HBW. Use cutting feed provided by the tool manufacturer.  It is worth trying a gradual increase in cutting speed to save time. Start from a low cutting speed. 

19. What is the difference between roughing and finishing?

Roughing is mainly to remove a large amount of material from the workpiece. Finishing is to improve surface finish and the tolerance of the workpiece.

20. What is turning?

Turning is a chip-forming cutting process where the workpiece rotates in a lathe. The resulting shape will have rotational symmetry. 

The information in this report is only applicable to SSAB’s products and should not be applied to any other products than original SSAB products. 

This report provides general results and recommendations for SSAB steel products. This report is subject to SSAB’s Terms of Use. It shall be the user's responsibility to verify that the information contained herein is correct and is suitable to be used for the particular purpose and application of the user. The report is intended to be used by professional users only who possess adequate expertise, qualification and knowledge for the safe and correct use of the results and recommendations in this report. This report is provided “as is”. The use of the report is at user’s own discretion and risk and that users will be solely responsible for any use of this report. SSAB disclaims any liability for the content or potential errors of this report, including but not limited to warranties and condition of merchantability or fitness for a particular purpose or suitability for individual applications. SSAB shall not be liable for any kind of direct or indirect damages and/or costs related to or arising therefrom, whether special, incidental, consequential or directly or indirectly related to the use of, or the inability to use, the report or the content, information or results included therein.