Description
The Procat reducing ring set 6-piece contains six steel reducing rings that adapt the centre hole of a saw blade to fit a smaller machine arbor. The sizes in the set are 20/16 mm, 30/16 mm, 30/18 mm, 30/20 mm, 30/25 mm and 30/25.4 mm. The first number is the diameter of the blade’s centre hole and the second the diameter of the arbor.
The reducing ring sits between the blade’s centre hole and the arbor and fills the difference in size. Without a ring, the blade sits off-centre on the arbor, so the tooth rim runs out, the cut widens and the clamping flange does not press evenly. The ring centres the blade on the arbor and transfers the clamping force of the flange evenly to the blade body.
The rings are steel and sized for a sliding fit: the ring goes onto the arbor by hand but without noticeable play. The thickness matches the thickness of the blade body so that the clamping flange presses against the blade, not the ring.
The most common need is a blade with a 30 mm centre hole on a machine with a 16, 18, 20, 25 or 25.4 mm arbor, and a 20 mm centre hole on a 16 mm arbor. The set covers these six combinations in one pack.
Intended use and suitability:
A reducing ring is used when the blade’s centre hole is larger than the machine arbor. The ring does not change the blade’s maximum permitted speed or the power of the machine.
- Circular saws and handheld circular saws: a blade with a 30 mm centre hole on a machine with a 16, 18, 20, 25 or 25.4 mm arbor.
- Table and mitre saws: using the same range of blades on several machines when the arbor sizes differ.
- Standardising your machine fleet: one blade stock serves machines from different manufacturers when the adapter sizes are available.
- Servicing and blade changes: replacing a lost or worn original ring without changing the whole blade.
- Extending the blade range: a blade that is available can be put to use even if its centre hole does not match the machine arbor.
Package contents:
- 1 pc reducing ring 20/16 mm
- 1 pc reducing ring 30/16 mm
- 1 pc reducing ring 30/18 mm
- 1 pc reducing ring 30/20 mm
- 1 pc reducing ring 30/25 mm
- 1 pc reducing ring 30/25.4 mm
- Blister pack with laminated product card
Features:
- Six adapter sizes: 20/16, 30/16, 30/18, 30/20, 30/25 and 30/25.4 mm cover the most common blade and arbor combinations.
- Steel construction: the ring withstands the clamping force of the flange and the operating temperature of the blade without losing its shape.
- Centring fit: the ring removes play between the blade and the arbor, which reduces runout of the tooth rim.
- Even clamping: the ring thickness is sized so that the clamping flange presses against the blade body.
- Set pack: all six sizes in one pack, so the right size is to hand when changing blades.
- Size markings: dimensions on the rings and the product card, so the size can be identified without measuring.
Technical specifications:
- Rings: 6 pcs.
- Adapter sizes: 20/16 mm, 30/16 mm, 30/18 mm, 30/20 mm, 30/25 mm, 30/25.4 mm.
- Marking: blade centre hole / arbor diameter.
- Material: steel.
- Fit: sliding fit on the arbor.
- Supplied as: blister, laminated product card.
Procat reducing ring set 6-piece instructions for use:
Choosing the size: Measure the diameter of the blade’s centre hole and of the machine arbor with a calliper. Choose the ring whose outer diameter matches the blade’s centre hole and whose inner diameter matches the arbor. The wrong size leaves play or prevents the blade from seating on the arbor.
Fitting: Switch off the power to the machine and remove the battery or plug. Clean resin and dust from the arbor, the clamping flange and the blade’s centre hole. Place the ring in the blade’s centre hole and slide the blade onto the arbor so that the direction of the teeth matches the direction of rotation of the machine. Fit the clamping flange and tighten the arbor bolt according to the machine manufacturer’s instructions.
Checking: Turn the blade by hand before starting and check that it runs true and does not touch the guard or riving knife. Start the machine without load and listen: runout can be heard as an even pulse.
Maintenance: Clean resin off the rings and store them dry in the original packaging so that the sizes stay separate. Take out of use any ring that is oval or scratched or has a dented edge.
Warnings:
- Switch off the power and remove the battery or plug before handling the blade and ring.
- Do not use a ring whose inner diameter is larger than the arbor. Play lets the blade move on the arbor and causes uncontrolled runout, kickback and the blade coming loose.
- Do not stack several rings on top of each other to get a fit. A stack does not centre the blade and transfers the clamping force to the rings instead of the blade.
- Do not modify the ring by filing, drilling or heating. Modification changes its dimensional accuracy and the strength of the material.
- Check that the clamping flange presses against the blade body and not the ring. Incorrect clamping lets the blade slip on the arbor.
- The ring does not change the blade’s maximum permitted speed; observe the limits of the blade and the machine.
- Keep out of the reach of children. The small metal ring is a choking hazard.
Frequently asked questions (FAQ):
Which sizes does the Procat reducing ring set 6-piece contain? Six rings: 20/16, 30/16, 30/18, 30/20, 30/25 and 30/25.4 mm.
How do I read the size marking? The first number is the diameter of the blade’s centre hole and the second the diameter of the machine arbor. The marking 30/20 fits a 30 mm centre hole on a 20 mm arbor.
What is the difference between 30/25 and 30/25.4? 25.4 mm is the metric equivalent of one inch. A machine with an inch-sized arbor needs the 25.4 mm ring; a 25 mm ring would leave play on it.
Can a ring larger than the arbor be used temporarily? No. A fit with play lets the blade move on the arbor, which leads to runout, kickback and the blade coming loose.
Are the rings suitable for both wood and metal blades? Yes, when the blade’s centre hole and the machine arbor match the ring dimensions. The ring does not affect the blade material or its range of use.
How do I check that the blade is centred? Turn the blade by hand with the power switched off and watch the distance between the tooth rim and the guard. An even distance all the way round means the blade is fitted centrally.
Recycling instructions:
Take reducing rings that are no longer used to metal recycling; the rings are entirely steel. Sort the plastic of the blister pack as plastic and the laminated product card as cardboard or, according to local rules, as mixed waste if the lamination prevents the cardboard from being recycled.
