1. Peb muab alloy sib tsoo log thiab grooving log ntawm ntau qhov ntau thiab tsawg rau kev sib tsoo thiab grooving ntawm roj hmab rollers. Thov sab laj peb rau lub log zoo tshaj plaws rau koj daim ntawv thov.
2. Xaiv qhov tsim nyog particle loj raws li qhov teeb meem ntawm Cots nrog txawv hardness, uas yog haum rau high-zoo sib tsoo thiab grooving ntawm cots.