Tool Guide

12.5mm Drill Bit

Drill Bits for Mushroom Cultivation

The choice of drill bit is based upon what type of spawn you will be using to inoculate the logs and the type of drill tool you will be using to drill inoculation sites into the logs. Never use low speed drill bits in high speed drills as shearing of the bit can occur resulting in serious injury or death.

Plug Spawn Drill Bits

For low speed drilling applications, where the drill tool is turning a less than 2500 rpm, the use of a brad point drill bit is recommended. An adjustable stop collar is available to set the drilling depth to a consistent depth.

For drill tools turning between 2500 to 5000 rpm, an 8.5mm screw tip hex shaft drill bit with stop is used. The screw tip pulls the bit into the wood and the stop strips the screw tip out so the bit can be easily removed from the drilled hole.

An 8.5mm chipped shaft screw tip drill bit with stop is used with tools turning over 5500 rpm such as our Express Drill Tool. The chipped shaft allows for a firm bite from the set screws that hold it in place in our angle grinder adapters (available in aluminum or steel).

Sawdust Spawn Drill Bits

For drill tools turning at 5000 rpm or less, the 12mm hex shaft drill bit with stop is the bit of choice. This is an excellent bit for 18V (or higher) cordless drill tools.

The 12mm and 12.5mm chipped shaft screw tip drill bit with stop are used with tools turning greater than 5000 rpm and the chipped shaft allows for a firm bite from the set screws that holds the bit in our angle grinder adapters. The extra 0.5 mm in width of the 12.5mm bit allows for easier insertion of spawn into the inoculation sites when used with either the Thumb Style Inoculation Tool, the Palm Style Inoculation Tool or the 12.5mm Okuda Inoculation Stick, the 12.5mm Okuda Hand Inoculator or the Okuda Pegasus Inoculation Machine.

The 13.5mm chipped shaft screw tip drill bit with stop is a specialty drill bit for the following tools: The 13.5mm Okuda Inoculation Stick, the 13.5mm Okuda Hand Inoculator, and the 13.5mm Pegasus. The advantages to this bit (and tools) are a faster spawn run and large first crop mushrooms. Slightly more spawn is used per log. This bit is NOT recommended for use with our palm or thumb style tools as it requires two "shots" to fill each inoculation site.

Express Drill Tool

Drill Tools for Mushroom Cultivation

There are a plethora of drill tools available to mushroom growers in the U.S., but the best one by far is our Express Drill Tool. This angle grinder turns at 10,000 rpm and when coupled with the appropriate drill bit, hole drilling becomes effortless. We offer a standard Express Drill Tool that comes with our aluminum angle grinder or a Deluxe Express Drill Tool that comes equipped with our steel angle grinder adapter.

Angle Grinder Adapters


If you already own a four inch angle grinder, you will need an adapter to make your life easier.

We offer two angle grinder adapters. The aluminum angle grinder adapter is domestically produced and has 5/8" x 11 TPI threading that allows it to fit onto most domestically branded angle grinders. It has one set screw to bite into our chipped shaft drill bits to hold the bit in place.

The steel angle grinder adapter is made for the industry in Japan and has two set screws for a positive grip on any of our chipped drill bits. The steel adapter comes with threading for U.S. branded angle grinders (5/8" x 11TPI) or in M14 threading (M14) for European and Australian branded angle grinders.

Due to safety concerns, the hex shaft drill bits and the 5/16" brad point drill bit will not fit into any of our angle grinder adapters.

Thumb Style Inoculator

Inoculation Tools for Mushroom Cultivation

We carry the widest selection of inoculation tools in the industry! Find one that fits your inoculation style.

The Thumb Style Brass Inoculation Tool is domestically produced and is the tool of choice for many growers as it is a one-handed operation. After jamming the tool into sawdust spawn to fill it, the thumb is used to depress the plunger filling the hole with spawn while your other hand is free to hold the log or point out things to your co-inoculators.

The Palm Style Brass Inoculation Tool works as above but it has a heavy-duty spring that is sturdy enough that you will need the palm of your hand to depress the plunger. This is a two handed operation so make sure the logs are straight as crooked logs are difficult to inoculate with this tool.

Okuda Inoculation Stick

Okuda Tools

These high quality tools are designed for durability and ease of operation and maintenance.

Okuda Inoculation Stick

The Okuda Inoculation Stick is constructed of solid stainless steel and is ergonomically designed for ease of operation. The tool can be adjusted to allow for spawn fill depths that then can be sealed either with wax or foam plugs. This is the only 13.5mm tool we offer that allows for wax to be used as a sealant (see the advantages of using 13.5mm above). Available in 12.5 or 13.5mm diameters.

Okuda Hand Inoculator

The Okuda Hand Inoculator is designed to fill and seal the inoculation site in one pass with the tool having to be refilled after each hole. The spawn is sealed with a foam cap. Using an Express Drill Tool, a two person inoculation crew can inoculate about 16 logs per hour. Available in 12.5 or 13.5mm diameters. This tool is the most cost effective means of inoculation for small to medium sized farms.

Okuda Pegasus Semi-Automatic Inoculation Machine

The Okuda Pegasus is designed for larger farms where thousands of logs are being inoculated each season. This air driven tool will fill the inoculation site in one pass, seal it with a foam cap, and refilled for the next inoculation site so the inoculation motion is non-stop. An option is also available that will allow for a wax seal, but this then adds another step to the process. A crew of two people, with one person drilling logs with the Express Drill Tool and the other inoculating with the Pegasus (foam cap option), can inoculate about 45 logs per hour! Available in 13.5mm diameter. The Pegasus requires a 2 HP air compressor to run efficiently.