Any weapon in Fortress Mode can be placed into a weapon trap. However, there are five trap components, or trap weapons, that are specifically for weapons traps (and two also have additional uses). As with any weapon, a total of up to 10 of these can be put in a single weapon trap, creating a true "Indiana Jones" type of threat to any beast of any size, and potentially simply making a fine mince (or paste, depending on the weapons) of lesser creatures. In the order they appear on the various menus, they are the menacing spike, the serrated disc, the spiked ball, the enormous corkscrew, and the giant axe blade.
All trap component weapons can be made out of metals (by a weaponsmith) or glass (by a glassmaker), with appropriate damage. Three can also be made out of wood (by a carpenter), as noted below, which can be useful in getting some heavy weapons traps set up before you have a steady smelting operation going, or if you are short on metal. Each trap component takes one unit of the material that you are using (eg. Each menacing iron spike will take one bar of iron). Note that although it is not possible to make giant axe blades or serrated disks out of wood, wooden ones can sometimes be bought from the embark screen. This is presumably a bug.
Trap weapons also provide the highest return of any weapon for melting, 120%-150%, compared to 90-120% for conventional weapons, which can be exploited for generating metal and training weaponsmiths. Trap components are a separate sub-section of a forge menu, but are at the bottom of the general glass furnace or carpenter's workshop menus.
Most of these weapons do make good trade goods, particularly large serrated discs and spiked balls.
 The 5 trap weapons
 Menacing spike
The menacing spike can be mounted in both traditional weapon traps and upright spike traps, which act quite differently. Its small contact size and high penetration depth makes it a decent choice against enemies with impale-able internal organs.
Menacing spikes can also be made from wood.
 Large, serrated disc
Large, serrated discs deal large amounts of damage, and have a tendency to sever their victims' limbs. While amusing, this can create several hauling tasks for dwarves as they have to move each severed body part to a butcher's shop or refuse pile. Large serrated discs attack three times, giving them a very high damage potential.
 Spiked ball
The spiked ball doesn't deal a blunt attack at all, but it does do three attacks with its spikes. Like the menacing spike, it has only a small contact area, but has a very low penetration depth compared to the menacing spike.
Low penetration depth edged attacks can still break bones with impact damage, just like blunt attacks do. In addition, if an edged weapon is unable to cut the material of the target's armor, its attack is converted to blunt type. Because the small contact area concentrates the force, spiked balls should be more effective against targets in superior armor than either serrated discs or giant axes.
Spiked balls can also be made from wood. If trees are not in short supply then wooden spiked balls make excellent trade items (except to the elves) due to the fact that spiked balls have an extremely high item value, almost to the extent of being a bug.
 Enormous corkscrew
The enormous corkscrew performs a small contact area deeply penetrating attack, much like the menacing spike. It is currently unknown which of these two trap components is the strongest over all.
Enormous corkscrews can also be made from wood.
 Giant axe blade
The giant axe blade is a very similar weapon to the large, serrated disc, but only strikes once, compared to the disc's three attacks. However, due to its larger size, its single attack is stronger than each of the large, serrated disc's. It is currently unknown which of these two trap components is the strongest over all.
However, if the variables behave like those of the wieldable weapons, size determines mass (along with material density) and mass determines impact (BLUNT) damage. An edged weapon, like the giant axe, only deals this type of damage when it is unable to penetrate armor, or if the target is large compared to its penetration depth.
This suggests that a steel serrated disc's multiple attacks will outweigh the giant axe blade's somewhat larger size in most cases. If only inferior materials are available, the giant axe might be better at hurting armored targets, but the disc's three attacks probably still outweigh this advantage.
 Data & comparison
|Name||Size||Number of hits||Contact Area||Penetration Depth||Wood?||Base Value|
|Giant axe blade||1600||1||100000||10000||No||66|
|Large, serrated disc||1000||3||100000||10000||No||126|
- (Most of this data has been compiled from raw/objects/item_trapcomp.txt)
 See also
item_trapcomp [OBJECT:ITEM] [ITEM_TRAPCOMP:ITEM_TRAPCOMP_GIANTAXEBLADE] [NAME:axe blade:axe blades] [ADJECTIVE:giant] [SIZE:1600] [HITS:1] [MATERIAL_SIZE:5] [METAL] [ATTACK:EDGE:100000:10000:slash:slashes:NO_SUB:1000] [ITEM_TRAPCOMP:ITEM_TRAPCOMP_ENORMOUSCORKSCREW] [NAME:corkscrew:corkscrews] [ADJECTIVE:enormous] [SIZE:1600] [HITS:1] [MATERIAL_SIZE:5] [IS_SCREW] [WOOD] [METAL] [ATTACK:EDGE:100:10000:drill:drills:NO_SUB:1000] [ITEM_TRAPCOMP:ITEM_TRAPCOMP_SPIKEDBALL] [NAME:ball:balls] [ADJECTIVE:spiked] [SIZE:1000] [HITS:3] [MATERIAL_SIZE:4] [WOOD] [METAL] [ATTACK:EDGE:10:200:strike:strikes:NO_SUB:1000] [ITEM_TRAPCOMP:ITEM_TRAPCOMP_LARGESERRATEDDISC] [NAME:disc:discs] [ADJECTIVE:large, serrated] [SIZE:1000] [HITS:3] [MATERIAL_SIZE:4] [METAL] [ATTACK:EDGE:100000:10000:saw:saws:NO_SUB:1000] [ITEM_TRAPCOMP:ITEM_TRAPCOMP_MENACINGSPIKE] [NAME:spike:spikes] [ADJECTIVE:menacing] [SIZE:1600] [HITS:1] [MATERIAL_SIZE:5] [IS_SPIKE] [WOOD] [METAL] [ATTACK:EDGE:10:6000:stab:stabs:NO_SUB:1000]