Download Metric O-Ring
Sizes and Standard Sizes Chart (PDF)
Sizes and Material Selection:
Of the many kinds of sealing technology available in products
manufacturing and machine design, the use of the o-ring is perhaps the
most common and extensive. O-rings are used in appliances found in our
homes as well as in heavy industrial machines like hydraulic cylinders
and jacks. They are also typically found in many types of hand tools
like pneumatic hammers, drills and air tools.
The selection of the right o-ring sizes is of critical importance and
the sizes of o-rings are determined by its internal diameter as well as
the diameter of its cross section area. The o-ring, when installed into
the mount, should seat nicely and with strict tolerance within the
recess of the mounting. The surface of the mounting that comes into
direct contact with the o-ring should be even so that pressure on the
o-ring is distributed evenly throughout. The o-ring, when compressed,
should exert a pressure against the contact surface of the mounting of a
value that is greater than the pressure of the fluid to be contained.
This is essential for the proper sealing of the fluid and ensures that
no leakage will occur. The selection of the o-ring should therefore be
made with the design and shape or size of the mounting contact surface
into consideration. The wrong size o-ring will result in sealing
Environments where sealing components are subject to abuse include that
of extreme temperatures conditions as well as exposure to corrosive
chemical media. Elastomeric seals have to perform under the most
demanding conditions, and failure would have implications in terms of
equipment downtime, environmental consequences and safety of operation.
Ge Mao Rubber
Industrial Co., Ltd.
No. 15, Kung Yeh East 4th Rd., Lukang, Chang Hua 505, Taiwan, R.O.C.