Independent comparisons. We may earn from shop links. More info

350mm diamond blade bore size and saw fit

Updated: October 2026

A 350mm diamond blade bore size is only one part of machine fit. The wheel must first be the diameter allowed by the guard, then its bore, maximum speed and flange arrangement must agree with the exact saw. This matters particularly with Stihl models: the TS 410 takes a 300 mm wheel, while the TS 420 takes 350 mm, so a similar name does not mean the same blade. Use the [350 mm diamond blade comparison](/hub/tool-accessories/350mm-diamond-blade) only after identifying the machine from its data plate and manual. A qualifying purchase can earn a commission at no extra cost to you.

A 350mm diamond blade bore size is only one part of machine fit. The wheel must first be the diameter allowed by the guard, then its bore, maximum speed and flange arrangement must agree with the exact saw.

Our top picks

PRODIAMANT PRODIAMANT 350 mm, 20 mm bore

Best overall

PRODIAMANT PRODIAMANT 350 mm, 20 mm bore
9.0/10about £54.78
View offer
PRODIAMANT PRODIAMANT 350 mm, 25.4 mm bore

Alternative

PRODIAMANT PRODIAMANT 350 mm, 25.4 mm bore
8.8/10about £51.83
View offer
OX OX Contractor CG15 350 mm

Best value

OX OX Contractor CG15 350 mm
7.4/10about £30.92
View offer
On this page
  1. 1.Start with 300 mm or 350 mm
  2. 2.Decide between 20 mm and 25.4 mm
  3. 3.If the numbers match but it will not run true
  4. 4.One recommendation, with a condition

Start with 300 mm or 350 mm

Stihl UK describes the TS 410 as a machine for 12-inch or 300 mm cutting wheels. A 350 mm blade from this category is the wrong diameter. It should not be forced beneath the guard or used with the guard altered. The permitted diameter is part of the saw's design. The Stihl TS 420 is the 350 mm model. Stihl UK states that diameter, and UK hire and dealer specifications list a cutting depth of about 125 mm. Treat that depth as a TS 420 figure. Do not swap or modify guards between the TS 410 and TS 420. If the model plate is damaged, pause the purchase until a dealer or competent technician confirms the saw.

Decide between 20 mm and 25.4 mm

UK dealer data lists the TS 420 blade as 350 x 20 mm, although the Stihl UK diameter line itself does not print the bore. The 20 mm listings here are PRODIAMANT B0171VPD7A, OX Contractor CG15-350/20, OX Pro V10-350/20 and GVHAKG B0FHQF6ZJJ. Sharing a bore does not make all four interchangeable. PRODIAMANT B0171VPDSO has a 25.4 mm bore. The listing does not say that a reduction ring is included. Do not order it for a 20 mm TS 420 merely because the captured price is slightly lower. The Husqvarna K 770 14-inch support specification lists a maximum 350 mm blade and an arbor described as 25.4/20 mm. Inspect the bushing and flanges supplied with that machine. A manufactured 25.4-to-20 mm reducing bush is a separate trade part. Use one only when both blade and machine instructions allow it. Never open a 20 mm bore to fit a larger shaft. Keep 22.23 mm separate: it is a common angle-grinder bore, not the TS 420 bore given by UK dealers.
PRODIAMANT PRODIAMANT 350 mm, 20 mm bore

Testsieger

PRODIAMANT PRODIAMANT 350 mm, 20 mm bore
9.0/10about £54.78
View offer

If the numbers match but it will not run true

The arbor, an approved reducing bush, the inner and outer flanges and the fastener form one system. Dirt, a reversed flange or mismatched parts can leave a wheel off-centre. Clean the contact faces and assemble them as the saw manual shows. One UK review in the shared PRODIAMANT material says a blade did not fit a Stihl saw without a washer that was not supplied. That is a complaint, not a manufacturer specification. If a stated 20 mm blade rocks on the shaft, return or resolve the parts. Check the direction arrow, restore the guard and perform the prescribed no-load run while standing out of the wheel's plane. The how to use a 350 mm diamond blade guide covers water, respiratory protection and the cut. None of the five retained Amazon listing summaries states a maximum rpm, so use the physical marking.

One recommendation, with a condition

For a confirmed TS 420 or another saw specified for a 350 mm wheel and a 20 mm arbor, start with a 20 mm blade whose material claim covers the job. The 20 mm PRODIAMANT is the more fully specified concrete option. OX Contractor is the lower-priced choice for its named general-masonry applications. GVHAKG is the only retained listing that names asphalt. Resolve the OX Pro V10 listing's 300 mm versus 350 mm conflict before considering it. For a saw whose documentation calls for a 350 mm wheel with a 25.4 mm bore, the 25.4 mm PRODIAMANT is the direct-bore listing in this set. No ring is listed. The concrete or asphalt 350 mm blade guide explains why the material changes the recommendation. For segment, kerf and EN 13236, read the 350mm diamond blade buying guide.

Common questions

Will a 350 mm blade fit a Stihl TS 410?
No. Stihl UK specifies 300 mm cutting wheels for the TS 410. A 350 mm blade belongs to a different machine class and should not be made to fit by changing or removing the original guard.
What bore does a Stihl TS 420 need?
Stihl UK states the 350 mm wheel diameter, while UK dealer specifications list the TS 420 at 350 x 20 mm. Confirm the bore in the manual and mounting parts for your exact machine rather than relying on the blade title alone.
Can I put a 25.4 mm blade on a 20 mm shaft?
Only with a proper reducing bush and flange arrangement expressly permitted by the blade and saw manufacturers. The 25.4 mm PRODIAMANT listing does not include a ring. Never run the blade loose or improvise a spacer.
What about a Husqvarna K 770?
Husqvarna's UK support data for the 14-inch K 770 lists a maximum 350 mm blade and a 25.4/20 mm arbor. Inspect the installed bushing and follow the exact manual because that dual notation does not mean any mounting arrangement is acceptable.
Why might a 20 mm blade still need attention?
The centre-hole number does not describe the flanges, bushes or condition of the shaft. One UK reviewer reported needing an unprovided washer on a Stihl, but treat that as a complaint rather than a universal requirement. Use only approved, correctly paired parts.
Is 22.23 mm the same as 20 mm?
No. They are different bore sizes. A 22.23 mm hole is common on angle-grinder discs and should not be treated as a direct fit on a 20 mm arbor. The wheel should locate correctly without play.
How deep will a 350 mm saw cut?
UK dealer listings put the TS 420 at about 125 mm. That is model-specific, not a universal depth for every 350 mm saw. Read the capacity for your exact machine and account for how the work is supported.

Related pages

Best 350 mm diamond blade

350 mm diamond blade

350mm diamond blade buying guide for saw and material

Concrete or asphalt diamond blade for a 350 mm saw

How to use a 350mm diamond blade on a petrol cutter

Sources

Public UK sources for silica, training, marking and saw size. amazon.co.uk listings for B0171VPD7A, B0171VPDSO, B0D8BQZKZQ, B0H4ZJ3T28 and B0FHQF6ZJJ were checked in October 2026. Prices move.

  1. HSE CIS54, dust from cutting and drilling (retrieved 17 October 2026)
  2. HSE INDG461, respirable crystalline silica (retrieved 17 October 2026)
  3. HSE, cutting paving blocks, kerbs and flags (retrieved 17 October 2026)
  4. HSE CN6, cutting paving and kerbs (retrieved 17 October 2026)
  5. PUWER 1998 regulation 9, training (retrieved 17 October 2026)
  6. FEPA safety leaflet, diamond saws on petrol cut-off machines (retrieved 17 October 2026)
  7. OSA, marking to EN 13236 (retrieved 17 October 2026)
  8. Stihl UK, TS 410 petrol cut-off machine (retrieved 17 October 2026)