The Pickering Punch



The Pickering Punch is a new sampling device developed by Agroisolab UK and designed to provide a quick and simple way to collect samples of timber directly from trees. The samples can then be used in reference databases to test against other samples of timber and see if the isotope signatures are similar. Patent protection is funded and a filing made at the UK Patent Office. 




For sampling with the Pickering Punch, the following is required:

  • A 2 or 3lb mini sledge hammer, i.e. a hammer with a shaft 10-14 inches long (not supplied in the Pickering Punch kit)

  • Sampling tubes (sent with the Pickering Punch kit, and also can be aquired through Agroisolab UK) OR small canvas/breathable bags (to prevent the growth of mould)

    • If using your own sample bags/tubes please ensure that each sample is appropriately labelled with identifying information on species, co-ordinate location, or GPS location, and an individual sample number that can be used to identify it among other samples

Sample tubes supplied by Agroisolab


Information that should accompany each sample (click to enlarge)



Please use the device with care and consider the following safety issues:

  • You will be using a hammer to knock a steel punch into a tree – consider wearing safety goggles and gloves.

  • The end of the Punch is sharp - keep the safety cap fixed on when not in use

  • Take care when hammering the Punch into the tree

  • Use caution when extracting the Punch with the heavy slide-hammer, keep fingers clear of the sliding weight and slide end

  • Make sure there is a clear area to swing the hammer - ensure that there are no trip hazards around and that any additional observers are at a safe distance (out of range if the hammer slips)

How to use


The principles on how to use the Pickering Punch are as follows:

  • A hollow punch can be easily knocked into a tree using a reasonably weighty hammer.

  • A plug of timber, 110mm long, is forced inside.

  • Extract the punch by hammering away from the tree – using a slide-hammer. 

  • The punch’s throat is designed so that at the first slide-hammer blow the plug is pinched off and extracted with the punch.

  • The slug of timber is released from the punch by tapping it out using the supplied rod.

  • Total cycle usually less than three minutes.

The details on using the Pickering Punch are as follows:


  • The punch is designed to be used across the grain of a standing tree. Don’t try planks of wood or fallen trees that have dried out – getting the punch out of dried timber is not easy and non-rooted timber can move, raising safety issues

  • Remove the black plastic cap – it pulls off. Put aside along with the black rod that fits through the centre hole of the plastic cap – take care not to lose the components.

  • Take one of the threaded steel caps and screw it into the threaded end of the punch. This is a very important part – the steel cap protects the punch from hammer blows. IMPORTANT: make sure the threaded cap is screwed all the way; don’t use a spanner – hand strength will do. Tighten till no thread is exposed.

  • Place Punch against tree at right angles to tree, parallel to the ground at, or just below, waist height. See Fig 1

  • Start with little taps until the punch is firmly in the tree. Then use increasingly strong and wide hammer blows to drive the punch to the limit of the thinner section. The total number of blows will vary – but should be around 20-35.


Please ensure that the entry point on the tree is not higher than just below waist height. The Punch is designed to be struck with full weight behind the hammer, so a swinging motion is neccessary. Adjusting the entry point any higher means that the Punch will not enter the tree easily.


Figure 1. Note end-cap with no exposed thread (stump from recently-felled tree - do not use Pickering Punch in old dry stumps).

Removing the punch


Once fully driven in (see Fig. 2) unscrew the threaded cap and attach instead, the threaded end of the slide hammer. Again, don’t use a spanner, but gloves might help. Fully thread the slide-hammer into the punch (see Fig. 3).


Figure 2. Punch fully driven in


Figure 3. Slide hammer attached to punch

Extract the punch by sliding the hammer weight back against the stop – the two nuts at the end of the shaft. 


IMPORTANT: don’t hold the weight with a tight grip. Use just enough grip to set the weight sliding back along the shaft. You are using it correctly when your hand slips off the weight when it is brought up short by the shaft stop. Wearing gloves is useful.


Experience shows that approximately the same number of blows are needed to extract the punch as hammer blows were needed to drive it in.

Extracting the core

  • Once out of the tree, unscrew the slide hammer and tap the plug of timber deeper into the tube until it exits via the stock (threaded) end. NOTE: the plug cannot be knocked out the other way - through the sharp end – as the sharp end has a restricted throat that will prevent this.

  • Store the plug in a roll of stiff cardboard sampling tubes provided by Agroisolab UK, or self-supplied sampling container (see above) and record species, longitude and latitude.

  • Repeat the process x2-3 per tree to get sufficient samples for referencing.

Video of Pickering Punch use



Agroisolab staff have tried the Pickering Punch prototypes on many English trees: Oak, Ash, Flowering Cherry, Sycamore, Beech, Scots Pine and Blackthorn (a hedge plant that grows to tree size if not pruned).

The punch extracted a plug to the same depth as driven 100% of the time. We are confident, therefore, that it will work in most, if not all temperate zone tree species. However, we are keen that the punch be tested on as wide a selection of timber types as users can find - tropical hardwoods in particular.

We very much welcome ideas and experiences you have using the Pickering Punch. Please email them to

Ordering Pickering Punch kits


Pickering Punch kits can be purchased through Agroisolab UK. For more information, please email

1 Welburn Business Park



North Yorkshire

YO60 7EP

+44 (0)1653 619444


  • LinkedIn
  • Facebook Social Icon
  • Twitter Social Icon
  • YouTube Social  Icon
  • Google+ Social Icon