The best deep hole markers, compared.
Top pick: tinshow (8 × 30 mm pens) Best value: Charles Bentley (Marxman twin pack) – About £9.75 for two markers with a stated 50 mm reach and 4.6 from 2,013 reviews. A drill dot, not a scribe line. Updated 22.10.2026.
A deep hole marker puts a drill dot or a short scribe line where a normal pencil cannot reach, usually through a bracket, a hinge or a back box. You use one when the fitting hides the wall and the drill still needs a centre. Choose removable chalk, an extendable graphite lead, a long mechanical nose or a long-nib felt pen. Match the stated reach to the hole, and decide whether the mark must wipe off. Reach and hole width belong together. A depth figure on its own does not show whether the tip will fit. Some extendable pencils state 100 mm in a 3 mm hole and 145 mm in a 6 mm hole, and those two figures are not interchangeable. Felt nibs are often much shorter. Chalk markers are commonly sold for about 50 mm. Those checks are set out in the [deep hole marker buying guide](/hub/diy-supplies/deep-hole-marker/sub/deep-hole-marker-buying-guide). No British Standard in these public sources sets a reach for carpenter markers, and a marker does not locate cables.
A deep hole marker puts a drill dot or a short scribe line where a normal pencil cannot reach, usually through a bracket, a hinge or a back box.
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Personal buying guide
Question 1 of 2
What mark do you need?
The tinshow pack is eight permanent markers with a stated 30 mm nib and a 2 mm felt tip, at £7.99, the same price as the SNAGAROG eight-pack. The listing line is 5.0 from 4 reviews. One UK review says only that it is ok. A 5.0 from four ratings is not a stronger buy than a 4.6 from 227 at the same price and the same stated 30 mm. Colour lists on the listing disagree: one field says blue, red, blue, and white, and the bullet says red, blue, black, and white. The printed item weight is 1 g, which is not a credible weight for eight pens. The ink is sold as waterproof.
Pros
Cons
Best for: You already accept a 30 mm permanent nib and you are not reading the 5.0 as proof it beats the larger sample.
Less suitable: You want a review file you can read, an agreed colour list, or a mark that wipes off.
Specifications
Common questions
How long is the nib?
The bullet says a 30 mm nib and a 2 mm felt tip.
Which colours are in the set?
The colour field says blue, red, blue, and white. The bullet says red, blue, black, and white. The two lists on the listing do not agree.
How many reviews support the 5.0 score?
The listing line is 5.0 from 4 reviews. One UK review says only that it is ok.
The QESSUVNC set is twelve permanent felt markers at £8.49, and the title says a 45 mm tip with a 2 mm point in red, green, black, and blue. The model field is 20/30/45mm, and one review says the pack has three nib lengths, so do not assume every pen is 45 mm. Across 22 amazon.co.uk reviews the line is 4.9, a small sample next to the 227 reviews on the 30 mm pack. The bullet calls the ink permanent, water and stain resistant, and fast drying. On amazon.co.uk this listing is ranked in stationery, not in DIY & Tools. A lid holder is mentioned in one review, not as a listed part.
Pros
Cons
Best for: You have checked that a 45 mm nib is in the pack you need, and 22 reviews are enough for you.
Less suitable: You need every pen to be one length, or a larger review file before you trust a 4.9.
Specifications
Common questions
Is every pen 45 mm?
The title and a bullet say a 45 mm tip. The model number field is 20/30/45mm, and one review says the pack has three nib lengths.
Which colours are included?
Red, green, black, and blue, three of each.
Is the ink permanent?
The bullet says permanent, water and stain resistant, fast drying ink. The waterproof field is true.
The RongPei five-pack is the cheapest felt set here at £4.99, sold as waterproof long-tip markers for wood, plastic, tile, and metal. The bullets do not give a nib length in millimetres. Across 10 amazon.co.uk reviews the line is 4.8. Reviewers say the ink marks wood and metal. One reviewer described the body as about 105 mm by 13 mm and wanted a longer nib; that measurement is a review, not a maker specification. The included-components field says No, while the pack is five pens. A 4.8 from 10 ratings is not a reason to treat this as a deeper marker than a pen that states 20 mm or 30 mm.
Pros
Cons
Best for: You want the lowest shelf price for a permanent long-tip pen and you can accept an unstated reach.
Less suitable: You are buying for a measured hole depth, or you want more than 10 reviews behind the star line.
Specifications
Common questions
How long is the tip?
The bullets say a long tip for deep holes. They do not give a length in millimetres.
Is it sold as waterproof?
Yes. The waterproof field is true, and the bullets say quick-drying, smudge-resistant ink.
How many pens are in the pack?
Five. The included-components field says No.
The Nicpro MG396 puts a 2.8 mm graphite line through a hole about 45 mm deep, using a fixed long nose rather than an extendable lead, at £11.99. The box holds two pencils, 26 leads, a sharpener, and a plastic box. Across 11,335 amazon.co.uk reviews the line is 4.7, the largest sample in this set, which is why it is the top pick. Reviewers use it for kitchen carcasses and general woodwork, and they also say the lead snaps if you lean on it and blunts at once on mortar. Painted surfaces do not take a bold line in those reviews. The listing does not claim the 100 mm or 145 mm reach used on the Tracer pencils, and the printed item weight of 18 g is light for two pencils plus 26 leads. It is a carpenter pencil, and the listing does not sell it as waterproof ink.
Pros
Cons
Best for: You want a spare-lead carpenter pencil for kitchen carcasses and general woodwork, and a 45 mm nose is deep enough.
Less suitable: You need 100 mm in a 3 mm hole or 145 mm in a 6 mm hole, or a removable chalk dot through a bracket.
Specifications
Common questions
How far does the Nicpro nose reach?
The listing bullet says a 45 mm elongated tip for small holes. It does not claim the 100 mm or 145 mm extendable reach used on the Tracer pencils.
What refills are in the box?
Included components are 2 pencils, 26 leads of 2.8 mm, 1 sharpener screwed into the top, and 1 plastic box.
Is the mark permanent?
No. It is a graphite carpenter pencil. The listing does not sell it as waterproof ink.
The YLYDMY pack is ten black permanent markers with a 20 mm head and a 1 mm tip, at £6.99. That head is for a shallow hole or a tight corner, not a deep bracket: the listing does not claim 30 mm or 45 mm. Across 61 amazon.co.uk reviews the line is 4.7. Reviews say the long head helps, and also that pens run out or the tips mash. The ink is sold as waterproof and quick-drying, so it will not wipe off the way chalk does. The bullet says to replace the cap when the pen is not in use. All ten pens are black.
Pros
Cons
Best for: You want a short permanent dot on metal or wood and a spare pen in the same pack.
Less suitable: The fitting is deeper than 20 mm, or the finish cannot take permanent ink.
Specifications
Common questions
Is 20 mm enough for a deep bracket?
The listing states a 20 mm head and a 1 mm diameter. It does not claim 30 mm or 45 mm.
Will the ink wipe off?
No. It is sold as a permanent marker with waterproof, quick-drying ink. The bullet says to replace the cap when it is not in use.
Which colours are in the pack?
The colour field and the ink colour are black, 10 pieces.
The Charles Bentley twin pack fires a removable green chalk dot through a fitting listed at up to 50 mm, at £9.75 for two markers. The listing says 250 bursts. Across 2,013 amazon.co.uk reviews the line is 4.6, the second-highest score here, which makes this the best value when you want a stated depth and a spare pen. Reviewers say the mark wipes off brick, wallpaper, wood, and steel. One review says the mark is UV reactive; that is a single review, not a specification. Twist the top so the pin enters the keyway to fire, then pull up and twist after use, or the bottle loses charge. It marks a drill dot, not a scribe line.
Pros
Cons
Best for: You are marking shelf brackets, hinges, or back boxes up to about 50 mm and want a second pen in the same order.
Less suitable: You need a graphite line on timber, a cavity deeper than 50 mm, or a mark that must stay on the wall.
Specifications
Common questions
How deep a fitting does this twin pack claim?
The bullet says it marks a fixing point through fitting depths of up to 50 mm.
Does the mark stay on the wall?
The bullet calls it removable green pigment. Reviews say it wipes off. One review also says the mark is UV reactive.
How should it be stored?
One review says twist the top so the pin enters the keyway to fire, then pull up and twist after use so the pin is not left engaged, or the bottle loses charge.
The single Marxman is a green press marker for shelves, hinges, and pipework at £6.39, and the listing does not state a depth in millimetres. Across 1,562 amazon.co.uk reviews the line is 4.6. Reviewers describe holding a bracket or a back box and pressing once for a green dot. It can arrive locked: twist the end so the plastic rib lines up with the notch before it will fire. One review says it fires a dot and cannot draw a line. Another reviewer put the standard model at about 45 mm in use; that figure is a review, not a millimetre on this listing. The listing marks it as not water resistant, and the item weight of 29 g does not match a bullet that says 50 g.
Pros
Cons
Best for: You already know the hole is shallow and you want one Marxman-style press marker at £6.39.
Less suitable: You need a stated 50 mm or 100 mm reach, a scribe line, or a mark that stays when the surface gets wet.
Specifications
Common questions
Does this listing state a depth in millimetres?
No. The bullets name shelves, cabinets, hinges, drainpipes, and electrical tubing, but they do not give a millimetre reach.
Why might it do nothing out of the box?
Reviews say it can arrive locked. Twist the end so the plastic rib lines up with the notch before it will fire.
Can it draw a line?
One review says it fires a dot of green through the hole and cannot draw a line.
The SNAGAROG pack is eight permanent markers with a 30 mm tip, three red, three blue, and two black, at £7.99. The bullet sells them for holes and narrow gaps, with waterproof, fast-drying ink. Across 227 amazon.co.uk reviews the line is 4.6, the largest felt-pen sample in this set. One review says only some pens worked and others arrived dried up. Another says the nib can disconnect from the shaft when the cap comes off. The line-size field is 0.5 mm, which is a fine line rather than a broad felt stroke. Xylene-free on the bullet is not a non-toxic claim.
Pros
Cons
Best for: You want a 30 mm permanent nib and a review file larger than the four-review pack at the same £7.99.
Less suitable: You need a mark that wipes off, or a nib longer than 30 mm with one agreed length.
Specifications
Common questions
How long is the nib?
The bullet says a 30 mm tip for holes and narrow gaps.
Is the ink described as permanent?
Yes. The bullet says permanent, water and stain resistant, fast drying, xylene free, and low odour. Xylene-free is not a non-toxic claim.
Did reviewers find every pen working?
One review says only some worked and others were dried up. Another says the nib can disconnect from the shaft when the cap comes off.
The Tracer Trueshot sprays a green chalk dot into a hole the listing states as up to 100 mm deep, at £11.45. The box lists a replaceable cartridge, a pocket clip, and a lanyard eye; a lanyard cord is not listed, and the bullet does not state a minimum hole width. Across 196 amazon.co.uk reviews the line is 4.6. Reviewers who like it talk about a clear dot, one-handed use up a ladder, and a refill. Reviewers who are less keen mention the end cap wearing, and the price against a hardware-shop chalk pen. The amazon.co.uk bullets here do not state a shot count, so a figure from another Tracer or Screwfix page is not a count for this listing. It is chalk, not permanent ink, and the listing weight is 60 g.
Pros
Cons
Best for: The cavity is deeper than about 50 mm and you want a refillable chalk spray rather than a felt nib.
Less suitable: You need a graphite line, a stated hole width, or the cheaper twin pack for fittings already covered at 50 mm.
Specifications
Common questions
What reach does the Trueshot listing state?
The bullet says it marks inside holes and cavities up to 100 mm deep. It does not state a minimum hole width.
Can the cartridge be replaced?
Yes. Included components are a replaceable cartridge, a pocket clip, and a lanyard eye. The bullet describes a quick-change cartridge. A lanyard cord is not listed.
Is the mark sold as permanent ink?
No. The writing-instrument form is chalk, and the bullet describes high-visibility green chalk.
The Tracer Pencil 2.0 extends a 2B lead to 100 mm in a 3 mm hole or 145 mm in a 6 mm hole, and those two figures are not interchangeable, at £16.79. The kit adds 12 replacement leads, a site holster, a pocket clip, and a built-in sharpener. Across 66 amazon.co.uk reviews the line is 4.6. Reviewers use the holster as a grip and say the 2B lead marks timber and, for some of them, metal and PVC. Leads blunt, which is what a soft grade does, and one review says the lead pushes back in. That clamp complaint is present, but it is not the pattern on the Pro listing. The body is described as sturdy metal, not aluminium.
Pros
Cons
Best for: You want a scribe line in a narrow hole and a holster, and you will match 3 mm holes to 100 mm and 6 mm holes to 145 mm.
Less suitable: You only need a 45 mm nose, a removable chalk dot, or you are buying this kit because you want an aluminium body.
Specifications
Common questions
Which hole width goes with which reach?
The same bullet says up to 100 mm in a 3 mm hole or 145 mm in a 6 mm hole. The two figures are not interchangeable.
What is in the kit?
12 replacement leads, a site holster, a pocket clip, and a built-in sharpener, plus the pencil.
Is the body aluminium?
This listing says a sturdy metal design. It does not say aluminium. Aluminium is the claim on the Pro kit, model AMK1-PRO.
The Tracer Pro is an aluminium pencil kit at £24.95, the dearest row here, with a stated lead of up to 145 mm, six leads, two holsters, and a sharpener. This listing does not pair 145 mm with the 3 mm and 6 mm hole widths printed on the Pencil 2.0. Across 551 amazon.co.uk reviews the line is 3.8, the weakest star line in the set. Several reviews say the button comes off, the body comes apart, or the lead retracts, will not stay out, or will not feed. Positive reviews mention the weight, the holster, and the long tip. One review says the Pro is a different size and the grey non-Pro holder does not fit. The line-size field of 0.7 mm does not match the 2.8 mm lead on the Pencil 2.0 listing, so treat 0.7 mm as a catalogue figure. Aluminium on the body is not evidence of a tougher clamp.
Pros
Cons
Best for: You want the aluminium body, two holsters, and a stated 145 mm lead, and you have read the 3.8 review line before you buy.
Less suitable: You are moving up from a plastic Tracer because you expect a stronger clamp, or you need the 3 mm and 6 mm hole pair written on the listing.
Specifications
Common questions
Does the Pro listing pair 145 mm with a hole width?
No. This listing says up to 145 mm. It does not repeat the 3 mm and 6 mm hole pair printed on the Pencil 2.0.
What do the reviews say about the lead?
Several reviews say the button comes off, the body comes apart, or the lead retracts, will not stay out, or will not feed. The listing score is 3.8 from 551 reviews.
Will a non-Pro holster fit?
One review says the Pro is a different size and the grey non-Pro holder does not fit.
Each score is the amazon.co.uk star line, scaled towards 40, plus the review sample, which stops at 25, plus whether reach, hole width and mark type are actually stated, plus shelf price against what the listing proves. Repeated review faults are subtracted. This is not a laboratory test. The highest score is the top pick. Best value is a different listing: a stated depth, a large review file, and a lower price per pen. A 5.0 from four reviews cannot lead.
Star line
40%The amazon.co.uk star average, scaled towards 40 points. A 4.7 line scores higher than a 3.8 line. Stars alone do not decide the row.
Review sample
25%The review count, rising with the sample and stopping at 25 points. A handful of ratings cannot outrank a file of hundreds or thousands.
Listing fit
20%Whether the listing states reach, hole width and mark type. A missing millimetre depth, or a mixed nib length, scores lower than a clear pair of figures.
Value
15%Shelf price against what the listing actually proves. A cheap pen with no stated reach does not take the value award. Repeated faults are deducted and are not a fifth weight.
Buy the job before the longest millimetre on the packet. A deep hole marker is a chalk dot, a graphite line, or a permanent felt dot, and they are not substitutes. Match stated reach to hole width. A high star line from four reviews is weaker evidence than a slightly lower line from a large file.
A deep hole marker puts a drill dot or a short line where a normal pencil cannot reach, usually through a bracket, a hinge or a back box. On amazon.co.uk the choice is removable chalk, an extendable graphite lead, a long mechanical nose, or a long-nib felt pen. Quality is the match between the stated reach and the hole in front of you, and whether the mark is meant to wipe off. Buy in this order. First the job: a removable drill dot, a scribe line, or a waterproof dot.
145 mm is not a universal reach. Tracer pencil pages pair 100 mm with a 3 mm hole and 145 mm with a 6 mm hole. The Pro listing states 145 mm and does not repeat those widths.
Chalk is sold as removable. Felt packs here are sold as permanent waterproof ink. A 20 mm nib is also short for a deep bracket.
The dearest kit is also the one with 3.8 from 551 reviews and a repeated complaint that the lead will not stay out. A 5.0 from four reviews does not overturn a larger sample at the same price.
The first check is the job, because these listings are not substitutes. Chalk leaves a removable drill dot. An extendable or thick-lead pencil leaves a scribe line. A long-nib felt pen leaves a waterproof dot that will not wipe off. Then read reach and hole width together. Tracer pencil pages state 100 mm deep in a 3 mm hole and 145 mm deep in a 6 mm hole. The Pencil 2.0 listing prints that pair at about £16.79.
Check whether the surface will show the colour, and whether the finish can survive permanent ink. Chalk is sold as removable. Graphite is a pencil line, not waterproof ink. Xylene-free on a felt bullet is not a non-toxic claim. Then check refills. Leads blunt, chalk runs out, and felt nibs dry or mash. The Nicpro box has 26 leads. The Pencil 2.0 kit has 12. The Bentley listing says 250 bursts.
Three typical situations, each with a recommendation from this comparison.
You want a graphite line on timber and spare leads. The Nicpro 45 mm set is the top pick at about £11.99, with 4.7 from 11,335 reviews, two pencils and 26 leads. The nose is 45 mm. It is the wrong pen if you need 100 mm in a 3 mm hole or a mark that wipes off a painted wall.
You want one press through a fitting and a mark you can wipe off. The Charles Bentley twin pack is best value at about £9.75, with a stated reach of up to 50 mm and 4.6 from 2,013 reviews. It leaves a drill dot, not a saw line. Deeper than about 50 mm is outside that listing.
The hole is deeper than a chalk pen states, and you still want a line. The Tracer Pencil 2.0 kit is about £16.79, with 12 leads and a site holster, and it prints 100 mm in a 3 mm hole or 145 mm in a 6 mm hole. Those two figures are not interchangeable. An aluminium body is not evidence of a stronger clamp.
The top pick is the Nicpro 45 mm mechanical set at about £11.99. It scores 8.5, the highest here: a 45 mm nose, 2.8 mm leads, two pencils and 26 refills, with 4.7 from 11,335 reviews. The lead snaps if you lean on it, and the reach is not 100 mm or 145 mm. Best value is the Charles Bentley Marxman twin pack at about £9.75. It scores 7.9, with a stated reach of up to 50 mm, 250 bursts, and 4.6 from 2,013 reviews. It marks a removable drill dot, not a scribe line. The Tracer Pro at about £24.95 does not take a badge: 3.8 from 551 reviews, and a repeated complaint that the lead will not stay out.
Charles Bentley (Marxman twin pack)
About £9.75 for two markers with a stated 50 mm reach and 4.6 from 2,013 reviews. A drill dot, not a scribe line.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources and the amazon.co.uk listings compared on this page. Updated 22.10.2026.
This page contains affiliate links. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the amazon.co.uk figures already stored for this set. This is not a laboratory test.
