直心力骨式網(wǎng)帶把左旋、右旋的螺線(xiàn)交互編入，并以直心力骨連接，力骨距未滿(mǎn)螺距兩倍的稱(chēng)為A2，力骨距大于螺距的稱(chēng)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. 表面平滑，可搬送不穩定的制品
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. 可用于高溫情況
Belt can be used at high tiemperature.
4. 網(wǎng)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