Material:Gcr15 SUS440C Thickness: HRC622 ( SUS440C : HRC58 ) Accuracy: g6 . h6 Roughness: ? 0.8 mm ( Rmax ) Outer diameter: 3 ? 120 ( Gcr15 ) 3 40 ( SUS440C ) Grade length : 100 mm 3010 mm ( 6000 mm is available ) Diameter : 100 mm ?5 mm Roundness : ? 3.0 mm ( Rmax ) Item : 20 mm WC20--500 mm Cylinder Liner Rail Linear optical axis ID: 20 mm Package: 4 pcs WC20--500 mm Cylinder Linear Rail Linear optical axis The cylinder linear rail can be machine end per request.We can drill holes and make thread too.If you need machine end, please send us the machine end drawing. Payment: All the payment must be made within 7 days. Shipping 1.All our items will be sent out via fast way--FeDex,DHL,UPS ,TNT and some other fast way. 2.Normally , we would send to any place.But some loctions may be vary on shipping. We set them into excluding locations.If you are in the list, please contact us for information. 3.Shipping date: DHL is arounding 3 -- 12 days. FeDex,UPS,TNT is arounding 7-- 14 days. 4.For some length and weight, DHL may be cheaper.But it is not always.We will choose proper carrier. Duty: We firmly believe there will be duty to the orders. Buyers must pay this fee. But we will do our best to help buyers to low the fee as possible.We would mark the reasonable declared price on the shipping invoice. It do work to most of buyers. Before After Purchase 1.If you have any question before or after purchase, please feel free to contact us. We will reply them as soon as possible. 2.If there is any problem on order, please contact us at once. We will solve them at fastest and friendly ways. Handling Time: Normally, we would send out all the orders in 3--5 days.We set 10 days is to avoid problem from. Packing: We have do a lot of work on packing. We would use hardborad and pearl wool to pack them.It can protect item from bending during shipping.