How to measure a Grip Ring Stem.
||The Grip Ring Stem is the most popular
stem used on office chairs and chairs with metal bases. The metal base normally
would have a steel tube welded into the ends of the legs. The caster stem is
inserted into that tube. Although most chairs require a 7/16" diameter stem,
some need a 3/8" diameter stem.
|If ordering a 3/8" Grip Ring Stem, please verify
your measurements. 95% of all customer returns are 3/8" Grip Ring Stems where
the customer measured incorrectly and really needed 7/16". You may even get a
phone call or an email from us to verify your measurements. It's costly for you
to have to exchange casters due to a measuring error.|
How does it
The Grip Ring is just that. It Grips the sides of the tube
when it is inserted. Also called an Expansion Ring or Friction Ring, the ring
compresses as it is inserted into the tube. It is the friction of the ring
against the side of the tube that holds the caster onto the chair. The position of the ring within the tube does not matter. It
does not line up with a slot or groove. It is the friction that holds it on.
This is why a shorter stem can be used as a replacement. If your stem is
longer than 7/8" ( the typical length of a replacement stem ) our caster will
work fine. The only important thing is that the depth of the hole be at least
as deep as the "Length of the Stem" so that the stem does not bottom out in the
hole. You can use a pencil to stick into the hole to check the
|Master Caster and some other
companies use the following letters to describe these stems:
"B" Stem is 7/16" x 7/8" Long
"K" Stem is 3/8" x 1" Long
you finish this step, click here to go to Step3 *************
|Measuring Tips &
|These are some Typical Stem measurements. Some
people have a hard time using a ruler so here is how the measurements will
look. 7/16" & 3/8 are very popular sizes for GRIP RING STEMS. 5/16" is the
normal size for a GRIP NECK STEM however a BED CASTER STEM will probably
|Use drill bits or other known size round devices
to measure the size of a hole diameter or the hole depth.
|It is very difficult to measure a round opject.
Here is a tip to use an adjustable wrench to create 2 parallel edges the same
size as the diameter of the "stem". Measure the width of the parallel edges and
that would be the diameter of the "stem".
|Open end wrenches are great measuring tools. Try
the 5/16" to measure the base of a GRIP NECK STEM and try the 3/8" or 7/16" on
a GRIP RING STEM. There should be a "slight" wiggle when using this
|Sometimes it's easier to measure the hole if
you're having a hard time trying to measure the stem diameter. This is also the
correct method for measuring the hole for a socket used with a GRIP NECK