直心力骨式91香蕉视频污把左旋、右旋的螺線交互編入，並以直心力骨連接，力骨距未滿螺距兩倍的稱為A2，力骨距大於螺距的稱為F2。
Left-wound and right-wound spirals are alernately Arranged and jointed with sraight rods.If rod pitch Is less than tw0-fold spiral pitch,belt is called A2. If rod pitch is equal to or greater than two-flod spiral Pitch,belt is called F2.

Advantages
1. 表麵平滑，可搬送不穩定的製品
Surface is flat and unstable itens can be carried.
2. 允許張力大，可搬送重負載物
Allowable tension is high and heavy load can be Carried.
3. 可用於高溫情況
Belt can be used at high tiemperature.
4. 網目細小，所以可搬送小物品 
Belt can have tight mesh and can carry small Items.

Typical specification of F2(nominal size) 
規格Specification       重量Weight(kg/m2 ) 
F2-8.5-30-6.0-4.0              43.5
F2-7.5-26-4.0-3.2              28.4
F2-6.0-20-3.2-2.6              14.8   
F2-4.2-15-2.6-2.0              20.2 
F2-3.4-14-2.0-1.4               20.2  
F2-3.0-12-1.8-1.4                20.2   
F2-2.6-10-1.6-1.2                11.4 

規格Specification       重量Weight(kg/m2 ) 
A2-9-16-4.0-3.2          30.5
A2-8-14-3.2-3.0          28.3
A2-6-8-2.6-2.0            21.0
A2-5-6-2.0-1.8             20.2
A2-4-3-1.4-1.4             19.3