1. Three Basic Dimensions
Pitch, Roller Diameter and Inner Width are referred to as the “Three Basic Sizes of Roller Chain.” When these three measurements are similar, roller chains and sprockets are dimensionally compatible.
2. Basic Parts
Link Plate
The plate is the component that bears the strain placed on the chain. Usually this is a repeated loading, sometimes accompanied by shock. Consequently, the plate should never only have great static tensile strength, it must also hold up to the dynamic forces of load and shock.
Pin
The pin is subject to shearing and bending forces transmitted by the plate. Simultaneously, it forms a load-bearing part (together with the bush) when the chain flexes during sprocket engagement. Therefore, the pin requirements high tensile and shear strength, resistance to bending, and must also have sufficient endurance against shock and use.
Bush
The bush is at the mercy of complex forces from all parts, especially from the repetition of shock loads when the chain engages the sprocket. For that reason, the bush needs incredibly high shock resistance. Furthermore, the bush forms a load-bearing part alongside the pin and as such requires great wear level of resistance.
Roller
The roller is subject to impact load as it mates with the sprocket teeth during engagement of the chain with the sprocket. After engagement, the roller changes its point of contact and stability. It is held between your sprocket the teeth and bush, and progresses the tooth face while receiving a compression load. Consequently, it must be resistant to use and still have power against shock, fatigue and compression. (RS25 and RS35 are bush chains , nor have rollers).
Roller Link
Two bushes are press match two roller link plates and rollers are inserted to allow rotation around the exterior of the bushes during Drive Chain procedure. This is actually the same 
for solitary and for multi strand chains.
Pin Hyperlink and Intermediate Plate
The pin link includes two pins that have been press match two pin hyperlink plates. In the event of multi-strand roller chain up till size 08B, an intermediate plate is definitely put into the pin link. In the event of multistrand roller chain above size 08B, two intermediate plates are put into the pin hyperlink. The intermediate plates are slip fit for standard roller chain and press match for Extremely roller chain.