How Powerful of a Medieval Crossbow is Needed to Penetrate Mail? (2024)

Alan Williams tested a bodkin arrow with an 18 degree point in which it needed 80 Joules to penetrate the mail and an additional 40 J to penetrate the padded jack underneath (and still go far enough to at least injure the wearer).

"Some modern (mild steel) mail, backed by a quilted jack, was tested. A piece of 15th century mail was also tested".

"with a simulated bodkin arrowhead (18 deg point); at 80 J impact, two links were broken; at 100 J, in addition, the jack was holed completely. At 120 J the mail was completely defeated, that is two links were opened out ,three others bent, a 5 mm diameter hole put through the jack, and a 35 mm dent in the plastilene beneath".

"an impact energy of 120 J (from a simulated arrow) broke two links and completely penetrated the jack"

-Knight and the Blast Furnace, pg 942-943

Surprisingly his thicker mail made by Erik Schmid was still defeated at the same 120 J, even though it did much better against swords and lances.

Draw weight alone is not enough to determine the joules of a projectile. Todd Todeschini's 1200 lb steel windlass crossbow shot to 140 Joules. Andreas Bichler's 1200 lb composite cranequin crossbow shot to about 200 Joules, but when shot in the middle of a moist summer, the same crossbow only shot to 168 Joules.

Cranequin crossbow (1200lb), shot at around -6 degrees Celsius
Powerstroke: 7.48 inches
Potential energy (linear): 507.12 Joules
81.1 g bolt – 69.85 m/s – 197.84 J - 39 % efficiency
98.1 g bolt – 64.17 m/s – 201.98 J - 40 % efficiency
105.1 g bolt – 61.47 m/s – 198.56 J - 39 % efficiencySame Cranequin crossbow (1200lb), shot at around +30 degrees Celsius
Powerstroke: 7.48 inches
Stored potential energy: 507.12 Joules
82 g bolt – 64 m/s – 167.94 J - 33 % efficiency

HackneyedScribe said:

Alan Williams tested a bodkin arrow with an 18 degree point in which it needed 80 Joules to penetrate the mail and an additional 40 J to penetrate the padded jack underneath (and still go far enough to at least injure the wearer).

"Some modern (mild steel) mail, backed by a quilted jack, was tested. A piece of 15th century mail was also tested".

For modern mail:

"with a simulated bodkin arrowhead (18 deg point); at 80 J impact, two links were broken; at 100 J, in addition, the jack was holed completely. At 120 J the mail was completely defeated, that is two links were opened out ,three others bent, a 5 mm diameter hole put through the jack, and a 35 mm dent in the plastilene beneath".

For 15th century mail:

"an impact energy of 120 J (from a simulated arrow) broke two links and completely penetrated the jack"

-Knight and the Blast Furnace, pg 942-943

Surprisingly his thicker mail made by Erik Schmid was still defeated at the same 120 J, even though it did much better against swords and lances.

Draw weight alone is not enough to determine the joules of a projectile. Todd Todeschini's 1200 lb steel windlass crossbow shot to 140 Joules. Andreas Bichler's 1200 lb composite cranequin crossbow shot to about 200 Joules, but when shot in the middle of a moist summer, the same crossbow only shot to 168 Joules.

Cranequin crossbow (1200lb), shot at around -6 degrees Celsius
Powerstroke: 7.48 inches
Potential energy (linear): 507.12 Joules
81.1 g bolt – 69.85 m/s – 197.84 J - 39 % efficiency
98.1 g bolt – 64.17 m/s – 201.98 J - 40 % efficiency
105.1 g bolt – 61.47 m/s – 198.56 J - 39 % efficiencySame Cranequin crossbow (1200lb), shot at around +30 degrees Celsius
Powerstroke: 7.48 inches
Stored potential energy: 507.12 Joules
82 g bolt – 64 m/s – 167.94 J - 33 % efficiency

Click to expand...

What an awesome answer!

HackneyedScribe said:

Alan Williams tested a bodkin arrow with an 18 degree point in which it needed 80 Joules to penetrate the mail and an additional 40 J to penetrate the padded jack underneath (and still go far enough to at least injure the wearer).

"Some modern (mild steel) mail, backed by a quilted jack, was tested. A piece of 15th century mail was also tested".

For modern mail:

"with a simulated bodkin arrowhead (18 deg point); at 80 J impact, two links were broken; at 100 J, in addition, the jack was holed completely. At 120 J the mail was completely defeated, that is two links were opened out ,three others bent, a 5 mm diameter hole put through the jack, and a 35 mm dent in the plastilene beneath".

For 15th century mail:

"an impact energy of 120 J (from a simulated arrow) broke two links and completely penetrated the jack"

See Also

Collections: Punching Through Some Armor MythsCan A Longbow Pierce Plate Armor?Can A Crossbow Pierce Plate Armor?Modern Bow Hunter vs. Medieval Knight

-Knight and the Blast Furnace, pg 942-943
It
Surprisingly his thicker mail made by Erik Schmid was still defeated at the same 120 J, even though it did much better against swords and lances.

Draw weight alone is not enough to determine the joules of a projectile. Todd Todeschini's 1200 lb steel windlass crossbow shot to 140 Joules. Andreas Bichler's 1200 lb composite cranequin crossbow shot to about 200 Joules, but when shot in the middle of a moist summer, the same crossbow only shot to 168 Joules.

Cranequin crossbow (1200lb), shot at around -6 degrees Celsius
Powerstroke: 7.48 inches
Potential energy (linear): 507.12 Joules
81.1 g bolt – 69.85 m/s – 197.84 J - 39 % efficiency
98.1 g bolt – 64.17 m/s – 201.98 J - 40 % efficiency
105.1 g bolt – 61.47 m/s – 198.56 J - 39 % efficiencySame Cranequin crossbow (1200lb), shot at around +30 degrees Celsius
Powerstroke: 7.48 inches
Stored potential energy: 507.12 Joules
82 g bolt – 64 m/s – 167.94 J - 33 % efficiency

Click to expand...

Fom what I have seen, there is a huge difference in penetration ability between stylesof arrow/ bolt head, with the needle bodkin style having the best ability. I assuming Alan.used riveted meail? Note, wrought iron would probably perform better that steel, more likely to give and deform than break.

Also, do you what the same value is for scale, lamilar armor? I would be curious to see how they compare.

PS - Excellent response.

Alan used historical mail gusset for one, and a mild steel mail by replica maker Erik Schmidt. As I said the bodkin tested had an 18 degree point, so a needle bodkin (better for penetrating mail or plates < 1mm thick) would require less than 120 J to defeat mail.

On the metallurgy of his mail, Alan said: "Some modern (mild steel) mail, backed by a quilted jack, was tested. A piece of 15th century mail (This was that specimen described in Williams (1980) as a 15th century mail gusset) was also tested. This was made of a low-carbon steel hardened by quenching. The performance was closely similar, but slightly inferior."
On another page he said: "Erik Schmidt supplied some modern mail for destructive testing".

Alan Williams only tested against mail and plate, not lamellar or scale.

However, Skallagrim used a 976 lb crossbow made by replica maker Tod Todeschini to shoot at scale, riveted mail (by Stephen Rhodes based on Viking Age finds), (terrible quality) lamellar, and good quality ......plate. The results of which I already mentioned in other threads. But in summary:

......plate resisted completely
Lamellar scales may be popped off (note Skallagrim stated that the lamellar bindings were of terrible quality and he snapped one of the threads by hand), but managed to resist all shots except the one shot which hit a section that had a scale popped off from a previous shot
Scale armor failed to resist most shots, due to the scales being only bound on one side, so arrows don't always need to penetrate the scale but only need to push the scales aside.
Riveted Mail was shot at only once by the 976 lb crossbow. It didn't resist.

The 976 lb Medieval replica crossbow was made by Tod Todeschini. Before he shipped the crossbow to Skallagrim, he shot it through a chronograph. The 976 lb crossbow sends a 96 gram bolt to a speed of 47.9 m/s, resulting in 110 Joules. The scale thickness for the scale and lamellar armor tested was 0.8 mm thick.

Williams tested two samples out of hundreds of different types of mail. The two examples that Williams tested were not meant to be worn alone, but in combination with plate armour. Standalone mail tended to be heavier and the best of this had a much tighter weave. You'd need a much heavier bow to penetrate these variants.

In this video they show one example with a weave so tight that a needle can't be poked through it.

This video should be required viewing for anyone interested in historical armour.

William said one of his mail was a gusset, which was meant to be worn in the joints of plate armor where plate doesn't protect.

The more protective set William does not say whether it was meant to be standalone or not. However, it was more protective to swords and lances than the mail gusset, though still failing at the same amount of joules to an 18 degree bodkin arrow. So this meant either it had a tighter weave, or it meant that modern mild steel was more protective than historical low carbon steel mail.

I know Williams' book very well; I've been citing it for the last 15 years. I also personally know Eric Schmid and have stayed at his house and spent time in his workshop. He was never happy with the mail he made for Williams' test and reckons that he could do a better job today. In any case, Williams' book is excellent; it is the definitive work on this subject, but you can't use it without taking its limitations into account.

The main problem is that Williams only tested two types of mail. There are hundreds of variants. Some are heavier, some are lighter, some have tiny links, some are made from hardened steel, some have a weave so dense that they have lost all flexibility, some are made from different patterns such as 6-in-1 or 8-in-2. All that can be said is that a heavy bow shot at short range stood a good chance of penetrating Williams' samples. It tells us nothing about how all of the other kinds of mail might resist a bow. It is like shooting a 3mm steel plate and pretending that the results are valid for a 1mm plate and a 6mm plate too.

We have primary sources telling us that some types of mail were considered proof against all weapons including heavy bows and mounted lances. According to Ffoulkes, the French called it "les mailles de tout botte". The fact that they had a specific term for it implies that other types of mail were not so protective. We also know for a fact that sometimes a fighter would wear two layers of mail or a layer of mail under another kind of armour, which raises many more questions. You can't just shoot a piece of mail without knowing the context. Suppose your arrow goes through a particular sample but you later learn that this mail variant was always worn under another type of armour? It would have been a complete waste of time and money because it tells us nothing about how this armour performs in battle.

I am not huge fan of Lindybeige, but I like this video of his.

He shows on authentic piece of armor that there were many kinds of mail links on single set of armor. So, penetrating it low on the arms or legs would be much easier, than doing so on the chest or shoulders for example.

Visigoth Panzer said:

Would I be safe in assuming that the heaviest mail couldn't be penetrated by any handheld crossbow?

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That's what the sources imply. There must have been a reason why everyone didn't wear this kind of mail. It might have cost too much, or been too heavy, or had flexibility issues. One wonders why some fighters chose to wear two mail shirts instead of one shirt made from this super protective mail. I covered some of these issues here.
https://myarmoury.com/feature_mail.html

janusdviveidis said:

He shows on authentic piece of armor that there were many kinds of mail links on single set of armor. So, penetrating it low on the arms or legs would be much easier, than doing so on the chest or shoulders for example.

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Exactly. Mail armour was made just like plate armour. It was heavier and denser over vulnerable areas and lighter where it was less likely to get hit, or where more flexibility was needed, or where it was overlapped by another piece of armour.

Dan Howard said:

Exactly. Mail armour was made just like plate armour. It was heavier and denser over vulnerable areas and lighter where it was less likely to get hit or where more flexibility was needed or where it was overlapped by another piece of armour.

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When I was a kid I think I saw at least one suit at the Met that had two layers over the heart area, iirc. I think it was European and had some metal poured on that area with marks stamped on it.

HackneyedScribe said:

Dan, I hope you can ask Eric Schmid about the weave and thickness of the armor he gave Williams for testing, and compare it to the weave/thickness of mail designed to be worn by itself.

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We don't know which kinds of mail were intended to be worn alone and which were intended to be worn as a layer. All we know is that they had this distinction and that the former tended to be heavier than the latter.

Dan Howard said:

That's what the sources imply. There must have been a reason why everyone didn't wear this kind of mail. It might have cost too much, or been too heavy, or had flexibility issues. One wonders why some fighters chose to wear two mail shirts instead of one shirt made from this super protective mail. I covered some of these issues here.
https://myarmoury.com/feature_mail.html

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Very informative.

Dan Howard said:

That's what the sources imply. There must have been a reason why everyone didn't wear this kind of mail. It might have cost too much, or been too heavy, or had flexibility issues. One wonders why some fighters chose to wear two mail shirts instead of one shirt made from this super protective mail. I covered some of these issues here.
https://myarmoury.com/feature_mail.html

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What are the properties of this mail as opposed to the usual mail meant to be worn by itself? Ie, metallurgy, link thickness, link diameter, etc, etc.....

We don't know which kinds of mail were intended to be worn alone and which were intended to be worn as a layer. All we know is that they had this distinction and that the former tended to be heavier than the latter.

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There are societies in which the vast majority of mail was meant to be worn by itself, mostly ancient cultures like the Romans or Celts (not Late Romans). We could at least know the Lorica Hamata was meant to be worn by itself with maybe a jack beneath, so what about the thickness of rings for most of the Lorica Hamata? Perhaps they could be compared with Medieval mail meant to be worn by itself.

HackneyedScribe said:

What are the properties of this mail as opposed to the usual mail meant to be worn by itself? Ie, metallurgy, link thickness, link diameter, etc, etc.....

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We won't know that until someone finds a text telling us how this mail was distinguished from other types. All we have are people like me who can make an educated guess based on decades of research and experimentation.

There are societies in which the vast majority of mail was meant to be worn by itself, mostly ancient cultures like the Romans or Celts (not Late Romans). We could at least know the Lorica Hamata was meant to be worn by itself with maybe a jack beneath, so what about the thickness of rings for most of the Lorica Hamata? Perhaps they could be compared with Medieval mail meant to be worn by itself.

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Arbeia is the best example we have of Roman mail. The links are pretty chunky with a dense weave but we don't know how much material was lost while it was underground for two thousand years and how much material was lost during the restoration process. Every tenth of a millimeter makes a big difference in the strength of mail armour.

This was a post from another from forum made by the very same Eric Schmid:

Good to be back.

To you and I it may indeed take quite a few hours to construct something of this nature. However, with the manufacturing capabilities of the Roman industrial machine, it may have not been as bad as we imagine. The use of both iron and bronze sclaes could have been purely for ornamentation.

On another note, there always seems to be controversy surrounding how well mail actually worked with regards to weapons. One of the things I did on this trip was to have some of my mail tested by professionals at the Royal Military College at Shrivenham, UK. Now remember you heard it here first. This will probably get posted elsewhere, but it was here first.

Now, the piece tested was a 6" x 6" square of mail made in the Viking fashion of alternating rows of both riveted and solid links.

The round section riveted links were made of mild steel wire roughly 1.5mm thick. The hole in the lapped ends was pierced so that the if viewed in the parallel plane the hole would resemble and hour glass. The rivets were mild steel as well and were round. The joints were set with a pair of specially shaped tongs. The size of the links was roughy 6-7mm inside diameter.

The solid or whole links were made of square section pure iron and were punched from a sheet. The thickness was equivalent to the riveted links.

I know some of you are thinking to yourselves that because I used mild steel it negates the test. Well, in a way yes, but... because of recent research by Dr. Alan Williams it has been concluded that mild steel reacts in much the same way as medieval iron. Anyway...

This piece of mail was placed over a piece of padding made to represent an aketon, which was placed over a substance used to mimick the human body. Something like a hard wax. The padding however was not adequate. It was roughly 1/4" thick. It should have been the traditional four fingers thick batting and then quilted. Believe me, I have had beach towels thicker than this.

All of this was placed under a drop tower. The weapon fastened to this machine was a pointed lance head. Nasty looking bastard. Basically it was made to represent a war lance. Three tests were performed at 40, 50 and 60 joules of energy. The only one that finally compromised the mail was the 60. It did not rupture a link, but rather sheared through it. Not once in all of the tests did the lapped joint fail. Were the padding more substantial I feel the mail would have held out longer, but that may not have been necessary. This is due to the fact that 60 joules of force is the equivalent of a couched lance with a graper and an arret.

That is a tremendous amount of force no matter how you look at it. Granted, the mail was earlier and pitted against a more powerful weapon than it would have normally faced which means that it would have withstood the weapons of its day quite well.

What am I getting at here you might ask? Well, it is just that there were more things influencing armour design that simply weapons. Alright, you can now ask questions and pick my brain. I am sure I forgot something.

The problem with Alan William's test is that I couldn't find the dimensions of the mail he tested. All we know is that it took 80 joules to penetrate the mail gusset and another 40 to penetrate the jack. The same amount of joules was required to penetrate Eric's mild steel mail with jack, so it's almost definitely around 80 joules to penetrate Eric's mail and another 40 for the jack.

Here Eric tested another mail, and this time the dimensions was given.
Ring thickness: ~1.5 mm
Inside diameter: 6-7 mm
Outside diameter: ~7.5-8.5 mm
Metallic composition: Mild steel (Eric says act the same way as Medieval iron)
Took 60 joules for a lance to penetrate, I assume the under-padding had minimal effect being too thin, so the vast majority of the joules went into penetrating the mail. It took far more joules for a simulated lance to penetrate the mail that Alan Williams tested (140 J for the medieval gusset+jack, and >200 J for Eric's mild steel mail+jack), so either
1. The lance head tested by Eric had a finer point (lance used by Williams had a fat 60 degree point), or
2. Both armors tested by Alan Williams was more protective, or
3. A little of both

Note: against a flat 1.9 mm sheet, it took 80 Joules for an arrowhead with 40 degree point to penetrate, and 75 Joules for an arrowhead of 18 degree point to penetrate.