Bobcat chain trencher attachments are common enough that aftermarket tooth options are widely available — which is useful because OEM pricing for consumable teeth adds up fast on a machine doing regular work. The challenge is that “fits Bobcat” covers a range of attachment models with different tooth requirements, and choosing the wrong spec based on a general compatibility claim wastes money and potentially damages the machine.
Here’s what actually matters when evaluating aftermarket options.
Start with the attachment model, not the carrier machine
The tooth spec is determined by the trencher attachment, not the Bobcat skid-steer or compact track loader it’s mounted on. A T595 carrier with an RT16 trencher attachment uses different teeth than the same carrier with an RT22. The same carrier machine can accept different trencher attachments with different chain widths, boom lengths, and tooth holders.
The attachment model number is on the attachment frame — usually stamped or on a label near the drive motor housing. That number, combined with the boom length and chain width, gives you the actual tooth specification rather than a general machine fit.
If you’re sourcing teeth for a machine you’ve serviced before, the easiest reference is the teeth currently on it — measure the shank diameter and length directly rather than relying on documentation that may have been for a different configuration.
Shank geometry is the critical compatibility spec
The shank is the portion of the tooth that seats into the holder welded to the chain. For aftermarket Bobcat teeth to work correctly, the shank must match the holder geometry precisely: diameter, length, and the flat or key that prevents rotation in the holder.
Undersized shank diameter causes movement in the holder, which leads to fretting wear at the seating interface. The tooth rocks rather than stays fixed, and both the tooth shank and the holder bore wear faster than they should. You’ll see this as oval-shaped holder bores and shanks with wear flats where there should be none.
Oversized shank diameter — even slightly — will make installation difficult and may deform the holder bore on assembly. This is less common with aftermarket parts but worth checking on the first tooth of a new batch before installing the full set.
Carbide tip geometry and grade for the work type
Bobcat trencher attachments cover a range of applications — landscape bed edging, irrigation installation, utility conduit, foundation drainage — and the tooth spec appropriate for each varies. A tooth optimized for clean sandy soil in irrigation work is not the right choice for a machine regularly hitting rocky fill or decomposed granite.
Aftermarket suppliers offer teeth in different carbide grades. The grade affects hardness (wear resistance) and toughness (impact resistance). For mixed conditions — the typical residential and commercial site where the ground is mostly soil but occasionally rocky — a medium cobalt content grade around 10–12% is usually the right balance.
If the machine is doing primarily soft soil in consistent conditions, a harder grade with lower cobalt content lasts longer. If there’s regular rock contact, a tougher grade with higher cobalt content prevents tip fracture. The wrong choice in either direction will underperform the correct grade noticeably.
Cup versus bullet tooth profile for Bobcat trencher applications
Bobcat trenchers are used with both cup (C-tooth) and bullet (conical) tooth profiles depending on the boom configuration. Cup teeth are designed for cleaner, consistent cuts and work well in soft to medium soil where material clearance and cut quality matter. Bullet teeth handle harder material and rock better because their conical geometry distributes impact load differently.
Most compact trencher applications use cup teeth because the work is typically in prepared soil. If a machine is being used for harder conditions than standard irrigation or landscape edging, confirming which profile the holder was designed for before ordering is worth doing — the holder geometry is typically designed for one profile, and substituting the other may result in improper seating.
Chain compatibility — don’t assume the tooth pitch matches
Aftermarket teeth for Bobcat trenchers need to match the chain pitch of the machine. The pitch — the distance between chain links — determines which holder positions accept teeth and at what spacing. An aftermarket tooth with the correct shank dimensions but wrong-pitch chain will either not reach the holder positions correctly or will be ordered in a chain configuration that doesn’t match the existing chain.
If you’re replacing teeth on an existing chain, you only need to match the tooth spec, not the chain itself. If you’re sourcing a complete chain and tooth set, both need to be matched to the boom sprocket pitch.
Evaluating a supplier claim of “fits Bobcat”
A supplier who can confirm compatibility by specific attachment model number — not just machine brand — is demonstrating more precise product knowledge. A compatibility chart that lists RT16, RT22, T4, and other specific Bobcat trencher attachment models by tooth part number is more reliable than a general “Bobcat compatible” claim.
Ask for dimensional drawings for the shank rather than just a compatibility list. A dimensional drawing tells you the supplier knows what they’re supplying; a compatibility list only tells you they’ve assigned a model to the SKU.
Batch consistency matters more than single-tooth inspection
On a full chain tooth set for a Bobcat trencher, you might be installing 20–40 teeth. If individual tooth shank dimensions vary significantly within a batch, some will be tight and some will be loose in the holders. That inconsistency produces uneven wear across chain positions — some teeth working harder than others, some wearing faster.
Ask a prospective supplier what their production tolerances are for shank diameter. Tolerances of ±0.1mm are reasonable for precision applications; wider tolerances are acceptable for larger machines but indicate less controlled manufacturing for compact trencher applications where the holders are smaller and fit matters more.
