How to name guide rails?

 The departure point of naming guide rails varies from country to country. Some name the guide rail according to the width of its aspect of guiding, such as T9, T16. While others name based on its weight, like 8LB, 12LB . However, we mostly name guide rail according to its width of bottom, for example: T70, T50.

What difference is there between cold-drawn and planed guide rails? 

 The process for cold-drawn involves stretching the material thus modifying its structure. Planing involves machining the guide rail by stripping the edgings.

Are the speed limits for the different qualities precise?

 No, the calculations for comfort are carried out using a mathematical model validated with practical tests, hence the speed limits set are approximate.

Why are the guide rails 5 meters long?

 The guide rails are 5 meters long because it is the appropriate manufacturing length and allows the parameters for straightening to be checked properly.

Do the guide rails have any surface treatment?

 No, the guide rails do not have surface treatments. On cold-drawn guide rails the cold-drawn process modifies the mechanical features of the material.