1. Three Basic Dimensions
Pitch, Roller Diameter and Inner Width are referred to as the “Three Basic Sizes of Roller Chain.” When these three sizes are identical, roller chains and Stainless Steel Chain sprockets are dimensionally compatible.
2. Basic Parts
Link Plate
The plate is the component that bears the strain positioned on the chain. Usually this is a repeated loading, occasionally accompanied 
by shock. As a result, the plate should never only possess great static tensile power, 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 power, level of resistance to bending, and must have sufficient stamina against shock and put on.
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. Consequently, the bush needs extremely high shock resistance. Furthermore, the bush forms a load-bearing part together with the pin and as such requires great wear level of resistance.
Roller
The roller is subject to impact load since 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 tooth and bush, and progresses the tooth face while getting a compression load. For that reason, it must be resistant to use and still have strength against shock, fatigue and compression. (RS25 and RS35 are bush chains and do not have rollers).
Roller Link
Two bushes are press fit into two roller hyperlink plates and rollers are inserted to permit rotation around the outside of the bushes during operation. This is the same for one and for multi strand chains.
Pin Link and Intermediate Plate
The pin link contains two pins that have been press match two pin link plates. In case of multi-strand roller chain up till size 08B, an intermediate plate is definitely added to the pin hyperlink. In the event of multistrand roller chain above size 08B, two intermediate plates are put into the pin hyperlink. The intermediate plates are slide fit for regular roller chain and press match for Extremely roller chain.