Basic Tool Production Techniques

Essentially the process of flintknapping is a controlled reduction by fracture within set parameters and rules dictated by the mechanics of the stone. Typically, those fracture mechanics are conchoidal on stone made almost entirely of silica. One some flakes the impact point is clearly visible with radiating concentric waves or ripples dissipating away. Those waves shows a snap shoot of the way the impact energy travelled through the stone when it was struck. By using different hammers, edge angles, strike power and speed, a knapper can predictably control how and where flakes detach from the nucleus of stone (usually called a “core”). I will cover some of these flaking techniques later in more detail. It is vitally important to have a confident grasp of the way stone breaks to improve working skill, this goes for both flintknapping and general stone masonry. To make things even more confusing, a cone of energy propagates when a strike makes contact with a flat surface of workable stone. This cone is known as the Herzian cone. One side of the cone can be seen on the flat, concaved side of a good flake, this side is the usually the lower part of the cone so appears more like a hump or bulb. This is the bulb of percussion. To add in more technical archaeology terminology; the flat, concaved side of a flake (that should have few or no ridges) is known as the ventral face of a flake. The ridged, convex side of a flake is known as the dorsal face. The flat area above the bulb of percussion where the flake was struck is called the platform. This can be prepared in a variety of ways that will be covered later.

Enough stone terminology for now, these terms will be used frequently so they are worth getting out of the way early on. To briefly cover some of the basic tools used for flintknapping, the most commonly used throughout the human past was the hammerstone. This is a tool that can be a simple beach pebble, but is hard enough to withstand the shock of being used to break flint. There is no rule as to the shape or size of hammerstones. However, it is worth having a variety of shapes and sizes that suit different tasks. The next tool is an abrader, these are rough stones such as sandstone that are used to roughen and blunt a flint edge back to thicker material. This allows flakes to be cleanly detached without crushing the edge because it is too thin and brittle. An abrader can be used fairly early on in a knapping sequence through to the final flakes, so is an important part of a knappers toolkit. The next type of hammer is known as a soft hammer. These are hammers made of osseous material such as bone or antler. Soft hammers can also be made of very dense wood such as box (Buxus sempervirens). Soft hammers are generally used in the latter stages of flintknapping, as they are especially good at thinning a potential tool without losing much of the flat surface profile. The earliest soft hammers in Britain come from Boxgrove (Chichester), they date to around 500,000 years BP. Finally the pressure flaker is used for the last stages of shaping, sharpening and retouching tools. These can be made of antler or copper. They are used with bodily pressure to push flakes from the edge of a tool or flake. They are commonly used to produce arrowheads or finish very thin tools such as spearheads. Other flintknapping tools are used, they will be mentioned in following parts where necessary. However, for the moment these are the basic tools.

Once you have some suitable hammerstones and the appropriate safety gear you can start to think about obtaining raw material. There are a few quarries around the UK that extract flint as large reject stone. Some will allow you to visit the quarry and select some flint, alternatively flint can be obtained from fields or field cairns (piles of stone removed from fields, usually located nearby). However permission to collect flint from land owned by someone else is always strongly encouraged. Flint can also be found in some river beds, this is almost certainly where Palaeolithic people sourced their flint. Being based close to a river such as the Bytham (now a lost Palaeo river) gave access to fresh water, prey and raw materials. Good flint can also be found on many beaches and coastlines around the UK, however on paper it is illegal to remove quantities of material, especially stone. Special research permission must be sought from the group or establishment that protects that particular stretch of coast. 

Now for the flintknapping itself. Unless near perfectly spherical, your block or nodule of flint should have a flat edge that can be used as an entry point. By this, I mean a first flake that will open up other flaking opportunities. With all flintknapping, the angle between the edge you are about to strike (the “platform”) and the surface where the flake should be detached from need to be under 90°. If this angle is much over 90°, the strike will cause the edge to crush and fracture in an undesirable manner.

Clean platform to make the first strike

Edge is clearly under 90° so is ideal for a good flake removal


I find the easiest and most comfortable way of holding the flint is so that the area you wish to strike is closest or facing your hand holding the hammerstone (below left). Your dominant hand should be holding the hammerstone in a way that is secure but keeps fingers clear of being crushed (below right).


You may wish to use your leg for supporting the flint if is too heavy to hold for prolonged periods. I would generally recommend using the same leg as your flint holding or “vice” hand. This allows unrestricted access for your hammer arm when making a strike. The movement of the strike itself should be so that the hammerstone makes clean, flat contact with the top of the flint, on the platform. The blow should be 0.5cm - 1cm from the edge, any further from the edge may require high amounts of power. It will hopefully become clear quickly that when the mass of the flint is greater at the edge you are working on; it requires a heavier blow. At this stage it is worth highlighting some troubleshooting.

If you are striking the edge and the only result is crushed edges and no flakes, you may be making your blows on the directly onto the edge. As stated earlier, blows must be above and at least 0.5cm from the edge to allow the flakes to detach.

If you feel you are holding the flint the correct way so that the area you want to strike faces the hammering arm but still get no flakes; you may be tilting the flint upwards at the last second before contact is made. This is a very common issue for novice knappers, the reasons why are unclear. You must make doubly sure that the striking surface or platform is flat when the hammerstone strikes. This can mean the flint needs to be tilting downwards slightly to ensure you strike to top of the platform. Experienced knappers typically tilt the flint slightly as this ensures clean contact and can encourage a better flake to be detached.

Avoid striking the actual edge of the flint, it will cause the edge to crush

A good strike should be just above the edge, this area is the platform


If flakes are not being detached despite a correct angle and strike, more power may be required. On a similar vein, more stability of the flint nodule may be required. More stability can be gained if the nodule is braced more against your leg. Opposite to this problem, if you feel you are striking but huge chunks are being detached in not quite the pace you wanted; the issue may be too much power. Generally, when novices use too much power the flint breaks uncontrollably due to the excess shock and because accuracy has been sacrificed for power. Flintknapping is a game of accuracy and good hand-eye coordination.

Hopefully you have managed to detach some flakes with sharp edges. So long as the inside angle is under 90°, you can make a strike where a flake has been detached. This will typically be on the opposite face of the flint. After detaching a flake, it is often worth putting the flake back in place on the core. This which demonstrate the outcome of your actions (whether they be correct or not!). This will hopefully show the result of your strike in relation to the flint core.

To round off this part, a few reminders:

  • Remember to keep blows to the edge, no further than 1cm from the edge (unless the edge mass is very thin)
  • The edge angle itself must be under 90° to flake easily
  • Blows must be made on top of the platform, not directly onto the edge
  • Experiment with the power required, but if the technique is correct and still no flakes; more power is required!
  • Try to hold the area you wish to strike so that your flint holding hand is clear and the striking area is closest to the hammerstone

Unretouched or non-worked flakes can be highly useful themselves for many tasks. This can make them tools in that sense without retouch work. For crafting involving bone or antler, I have often used flakes that would often be considered waste or “debitage”. This sheds an interesting light on how archaeologists interpret stone tools and the waste material. There are a number of different flake-based tools that can be crafted for different tasks and were used across early prehistory. Certainly one of the most common is the scraper. This tool first appears in the Lower Palaeolithic at some of Europe’s earliest sites. It continues to appear in a variety of forms well into the Bronze Age. Its purpose is typically associated with working animal hides, however it is likely to have been used for a number of functions. Scrapers need a steep edge that is hard, but blunt. A sharp scraper could result in cutting or scoring a hide undesirably. Generally a curved, steep edge is ideal for scrapers as it helps to work a wide area as well as starting to stretch the hide.

To make a scraper, a suitable flake must be selected. Suitable flakes can range in size from a couple of centimetres wide to well over 10cm in some cases. A gentle lip or curve in the flake profile is useful as it will make it a better working tool, although it is not strictly necessary (see below).

Once a flake has been identified, turn it so that the flat side or “face” with no ridges or cortex (skin of the flint) is facing upwards. This side of a flake is often concaved and may have gentle ripple marks, it is known as the vental side (see flake description in part 1). The other side, often with cortex and ridges is generally convex, it is known as the dorsal face. Keep that ventral face looking upwards so that the ridged, dorsal face is downwards into your hand. Now, with a small hammerstone, try to take some small flakes from the opposite edge to where you struck the flake to detach it originally (at the platform).  As with the larger nodule or chunk before, keep the strikes above the edge (so not striking directly onto the edge). Work around the end until you are left with a curved, worked edge. The curve can be wide or tight so long as it’s not pointed. Take a look on the opposite side of the flake frequently to check the flakes you are removing are both successful and clean removals. Crushed edges will shows tiny fractures that will show up white along the edge. A good, clean worked edge should have near none of the these micro-fractures and crushed areas.

A crushed edge, the attempted flakes have not travelled far


A cleanly flaked edge, the flakes have travelled further with no crushing


If you created an area of crushed flint it needs to be removed. This can be done with a slightly stronger strike a couple of mm deeper than the blows before. This extra power and depth into the flint should allow you to undercut the fracturing.

This edge might look suitable and feel blunt like a scraper, but it is crushed and will not work as well as it could do


To prevent further crushing the edge must be cleanly flaked, slightly harder flakes will undercut the crushed area


Once you feel your scraper is finished there is a good way to test it. Put the worked edge against the palm of the your and pull the scraper down as if it was being used on an animal hide. If you feel an abrasive edge but little else, it generally means there are some crushed areas of the scraper. If you feel the scraper gently biting into your skin as you pull down, it is well-made. This gentle biting and pulling at your skin is a simulation of what you want a scraper to do on a hide (see below).


A similar flaking approach can be taken to produce a piercer tool (above right) although instead of creating a convex, curved edge; the aim is to produce two smallerconcave curves either side of a point. Piercers have a variety of likely functions like scrapers. It is more than likely that they were used to make holes in materials such as leather, bone, wood, horn and stone. The tip of a piercer is generally fragile and can easily be broken during flaking, extra care must be taken. It is not unrealistic to assume before creating the point that it may break undesirably (it happens to the best of us!). Generally I try to aim for a long point that will still be highly useful if it becomes shorter after a break (with some light re-working at the break point).



For a sharp cutting edge it is best to use the fresh edges of a flint flake. These will be the sharpest edges that can be achieved during normal flaking. However if you wish to create an edge that is more serrated and longer-lasting (but not as sharp), a flake needs to be worked on both sides. Flaking on both sides brings bifacial working (flaking on both sides) into the foreground. When making a scraper it is very important to only flake on one side, however for a cutting tool it is important to flake on both sides. It would be easiest to start at the point we left the scraping tool. You can flake directly onto the flake scars of the steep scraping edge (above left). This will thin out that steep edge as well as produce serrations and an even cutting margin (above right).



Finally, a useful tool for cutting through small sections of wood: a flint saw. These are very useful for cutting hazel rods for arrow shafts, knife handles or giving a clean edge to a joint. They can also be used on bone and antler for trimming or shaping. For a saw you’ll need two thin flakes. One of the flakes will need one edge to be consistently thin and relatively straight (a mild curve is fine). Now you will be using a different technique to the tools before. Instead of directly striking the flakes you’ll use the flake (that is not destined to be the saw) to file notches from the saw flake. This will create a series of small points that will be the teeth. Hold the saw flake flat and put the edge of the file flake perpendicular to it, edge pointing upwards against the edge of the saw flake. Then drag down with the file flake, this should achieve a notch (above left). To progress, simply continue the notches at regular intervals along the edge. Do not be tempted to go back over your working once you have made the saw teeth, this will damage the teeth and reduce the effectiveness.


To see more Flint tools:

>> Palaeolithic Tools

>> Mesolithic & Neolithic Tools

I perform only authentic and primitive flintknapping, using tools and techniques that stone age man would have had ready access to, such as antler hammers. This excludes the use of modern tools, such as copper billets, stainless steel fluting machines and sawn slabs, as they have no prehistoric equivalent. Pressure flaking is done only with antler or other natural tips, although copper tips are used for Neolithic and Post-Neolithic tools. The use of leather gloves and safety glasses is for my protection only and generally makes the knapping process harder!!


Flint flakes can be ultrasharp (in excess of razor-sharp) and as they fly-off in various directions, therefore it is essential that knappers use eye-protection. Any demonstrations should warn the audience to remain at a safe position from the knapper (2-3m or more away) or if they are closer, it is advisable for them to wear eye-protection as well.


Not only are flint flakes can be extremely sharp, the mere exercise of crashing one stone against another with force can result in painful injury. For every knapping session it is advisable to wear strong leather gloves to provide some protection against flint flakes. Also knapping (using the ancient techniques) should be restricted to a few hours per day to avoid repetitive strains.

During demonstrations the audience should be warned not to pick-up flint flakes.


Repetitive knapping of flint, effectively bashing two rocks together, can be very loud (approximately 70-80 decibels) and annoying for those not participating. However researchers have also investigated the musical quality or Lithoacoustics of flint - the distinctive ring of good flint is unmistakable.


Ingestion of flint dust is lethal - in fact many 19th century gunflint knappers died of "consumption" - lungs diseases such as cancer, silicosis or pneumonia. Silicosis is a form of occupational lung disease through inhalation of crystalline particles of silica dust that causes shortness of breath, fever and, in some cases, cyanosis (bluish skin) that is irreversible with no cure. Silicosis ("Knapper's Rot" or the "Killer Dust") is progressive and signs of it, such as scarring in forms of nodular lesions in the upper lobes of the lungs, may not appear until years after exposure.

As the flint particles enter the lungs, they begin cutting the tissue, resulting in the body forming scar tissue over the sharp and unremoveable flint; this flint then cuts the scar tissue and forms even more scar tissue so large areas of the lung can be destroyed. Scar tissue is not the same as lung tissue and so the capacity of the lung to gather oxygen for the body is decreases over time.

Pneumonoultramicroscopicsilicovolcanoconiosis is another name for silicosis and at 45-letters, it was created to serve as the longest English word and is the longest word ever to appear in an English language dictionary.

According to Dr Edgar Collins (a former medical inspector of factories) in his Milroy lectures for 1915, Silicosis is mans oldest occupational disease. He suggested that Neolithic miners and Egyptian slave workers suffered from the disease. No evidence of Silicosis has been found in Neolithic miners and it is more probable that any dust inhaled during the mining process would be chalk dust which is not Siliceous dust; more likely the act of knapping would have caused this disease. It was first recognised by the UK Government in 1894, when regulations were introduced to protect quarry workers who worked on stone that contained more than 80% silica.



Silicosis showing as nodular mass on a chest x-ray

(image provenance / © unknown)

In Brandon (during the gunflint era) in one workshop of the eight men who worked there, seven died before they reached fifty, while in another a father and his three sons all died within four years of each other - all through Silicosis. In fact Dr Collis showed that over three quarters of the flintknappers at Brandon died of this problem and that workers with silicosis were more prone to contracting tuberculosis and more susceptible to infections.

Therefore it is advisable to perform any flintknapping in a well ventilated area or ideally outdoors.

Working with antler (and bone) is also hazardous, as they are porous and could contain all kinds of bacteria and other micro-organisms. Dust created when cutting antler will produce a strong odour and have a similar silicosis effect on the lungs as flint dust. Researchers are now finding some health benefits from antlers particularly for those who suffer from joint pain or people that need bone marrow and blood nourishment. Chinese medicine has used velvet deer antlers for generations to treat conditions such as arthritis and other related ailments.


It is a good idea to ensure that your tetanus jab is up-to-date and hands should be washed thoroughly after flintknapping. Have a basic first-aid kit handy (including plenty of plasters) and know where the closest emergency medical centre is.


The replication of stone tools obviously results in some waste that could be easily interpreted as genuine artefacts. It is vital that Flintknappers dispose of their debitage so that it cannot be found in the future and thought of as ancient. The best to dispose of waste is to have it crushed and mixed with quarry hardcore, which is used as gravel for building material etc. Most of the Flintknappers asked dispose their waste in a similar and responsible way. This may seem sensible as it would be mixed with waste from our modern day, but if it was a period of several thousands of years before found, the stone may be all that remained. Others ways to avoid confusion with ancient lithics is to sign the replication with indelible ink or to take digital photos of it. However the tool could be retouched to remove the ink or reshaped to render the photograph meaningless.

carry on knapping

Glossary of Flintknapping Terms


When a course stone is used to rub away a very thin edge of the stone so that when it is struck it will flake in a better way


A tool, typically made from stone, that was presumed to be used like a modern woodworker's chisel to work wood


An archaeological term meaning a group of different artefacts found in the same context


A slanted edge, created by pressure flaking with the purpose of re-sharpening


A tool that has been flaked on both sides


When the base of a tool is split or has a notch

Bi-Polar Core

A blade core that has two opposing striking platforms

Bird Point

Very small arrow heads possibly for killing birds


A small club made of antler, wood or copper with the purpose of being used in the form of a hammer and chisel


A flake of the stone that has parallel sides and has a length that is more than its width

Bulb of Percussion

Usually found in a stuck flake, a rounded bulb just beneath the place of impact on the flake

Bulbar Scar

A small mark on the Bulb of Percussion where a thin piece of the material has come off when it was struck


A piece of mainly flint that was found by the sea

Conchoidal fracture 

When a material scatters in a cone shape so the energy fans out form the point of impact

Cone of Percussion

Something that occurs in the material which is resulted from a short and sharp blow that was aimed at the materials surface


A prepared part of the stone which can have flakes removed from the edges which can be used as tools

Core Tools

Bifacial tools.


The outer chalky layer of flint

Crested Blade

The first flakes from a blade core that has been created using alternate flaking


The creation of a facet caused by different flaking which usually means a predictable flake. Usually used in blade core technology.


Term used by archaeologists to refer to the waste material left over when someone creates a stone tool

Direct Percussion

Blows made directly at the stone using hammers

Distal End

The end of a flake that has part of the striking platform

Dorsal Surface

A side of a flake that has marks from earlier flakes from the same place

End Snap

When one end is struck and a flake comes off the other end


Stress marks that radiate from the point of percussion.


Pieces of stone that were removed from the main piece during knapping


When a flake is removed that creates a channel on one or both sides of the tool making it easier to attach to a handle


Marks left on the core or tool when flakes were struck off it, this can show how a tool was made

Ground polished

An edge or surface that was smoothed by abrasion

Heat Treating

When some cherts are heated to make knapping easier

Hinge Fracture

When a strike goes wrong and a fracture appears that if not removed will result in a step fracture

Indirect Percussion

When pressure is put on a striking platform followed by a sudden blow, this is used in the style of a hammer and chisel

Isolated Platform

A platform that has been carefully isolated from the rest of the tool or nodule

Knap or Knapping

To break or strike stone to produce flakes and tools


A natural block of the material you are knapping


When a platform was perfect and angles and conditions were optimal

Overshot flake

A flake that was removed, but has run from one side of the tool to the other


Battering a stone with a hammerstone to form an intended shape by removal of very small chips


Any stage before the completion of a tool


The view of the flake or tool’s length, from the implements edge

Proximal End

The end of the flake that has the striking platform and/or bulb of percussion


The broadest view of the flake or tool

Platform Preparation

Adjustments made to the striking platforms


The redressing and correcting of controlled cores


A cross section through the width of the flake or tool

Shock Ripples

Rings and bands that radiate from the point of percussion.

Silicious Rocks

Stone other than flint which can fracture in the same way as flint (conchoidally)


Breaking up a nodule of the material into smaller workable pieces

Step fracture

A staircase of fracture that was the result of a hinge fracture, this can be difficult to remove; depending on the circumstances

Striking platform

A flat point that is to be struck and have flakes removed


The study of a decaying organism over time


A tool that has only had one side worked on

Ventral Surface

The side of the flake that has a bulb of percussion

Click here to learn more about Flint and how it was used by early man

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