Original Item. One-of-a-Kind. This is the most outstanding and scarce mine we have ever offered! This is the German Topfmine A4531, a High-Explosive-Blast (HE-Blast), Low-Metal-Content (LMC), PRESSURE-actuated, WW2 anti-tank landmine designed to be almost undetectable by Allied metal-detectors.

Unloaded or dummy grenades, artillery shell casings, and similar devices, which are cut or drilled in an BATF-approved manner so that they cannot be used as ammunition components for destructive devices, are not considered NFA weapons. This example is in total compliance and is NOT AVAILABLE FOR EXPORT.

Made mainly from compressed wood pulp, cardboard, tar and glass, it contained very little metal apart from the detonator. Shaped like a shallow dome with a central pressure-plate, it weighed about 20lbs and held roughly 12.5lbs of TNT. The landmine activated under heavy PRESSURE, crushing glass vials that triggered the explosive main-charge.

To enable the mines to be found by friendly forces, the mines were painted with a black sandy substance called Tarnsand (camouflage sand). Allied forces found that although the mines were undetectable by Allied mine detectors, German mine detectors could find the mines when they had been marked with Tarnsand. The secret of Tarnsand was maintained until after the end of the war, when it was discovered that it was a mildly radioactive substance and the German mine detectors incorporated a simple Geiger counter.

This example thankfully doesn’t show up as radioactive on our geiger counter, with a very small bit on the interior, so there is no worry of radioactivity. The mine shows extremely heavy wear which has worn away any and all original markings. The mine has a rough diameter of 13” and a height of 6 ¼” including the glass plugs.

The mine retains the central activating fuze well plug along with the integral glass fuze assembly plug. The mine also retains all three of the glass filler plugs, two small and one larger. The two smaller filler plugs were meant to hold the now-absent cardboard carrying handle. The body of the mine is heavily worn and torn with what looks like glue holding in the threading for the central activating fuze well plug. There may be markings somewhere on the mine, but we were unable to discern any. The side of the activating fuze well plug is marked 50, and the small interior plug piece has 13 next to what may be a maker mark.

The mine is meant to be set with the glass facing the ground, but in our opinion it really displays better with the glass pieces on top.

This is a truly outstanding piece, the very first and perhaps the last Topfmine A4531 we will ever offer, so don’t miss it! Comes ready for further research and display.

The Topfmine A had a flattened dome-shaped case with a raised flat circular pressure plate on the top surface surrounded by a circular shear groove. The case was normally made from pulped wood and cardboard mixed with tar for waterproofing. However, sometimes the case was made from bituminous coal waste. The SF 1 fuze was inserted into the underside of the mine and was placed inside a large glass plug which sealed the bottom of the mine. A secondary fuze well was provided on the bottom of this plug for installing anti-handling devices. The SF 1 fuze was constructed of glass and wood and contained a detonator and booster charge.

Pressure of approximately 330 pounds (150 kg) on the pressure plate caused the plate to shear off from the mine casing, collapsing down on the glass head of the pressure fuze. The glass head was driven downwards, crushing two glass vials of chemicals, which reacted together causing a flash, initiating the detonator, booster and finally the main charge of TNT.

Two versions of the mine were produced - a fully waterproofed version designated "To.Mi.A4531" and the normal "To.Mi.4531".

The Topfmine B (To.Mi.B4531) was broadly similar to the "A" version, the principal difference being a smooth case without a raised pressure plate. This version instead had an internal shear groove to prevent water from working its way into the mine and possibly deactivating it.

The Topfmine C (To.Mi.C4531 or Pappmine) changed the design to an eight-sided flattened cylinder shape, with a central glass fuze plug on the top. This design was very thin-walled and sympathetic detonation could occur if the mines were planted closer together than seven feet (2.1 m).

Totally inert, cannot be converted to an explosive device, not available for export. This item is completely legal within the USA. International Military Antiques, Inc observes all Federal, State and Local laws. Everything for sale on ima-usa.com is completely legal to own, trade, transport and sell within the United States of America.

All deactivated ordnance sold by IMA, Inc is engineered to be inoperable according to guidelines provided by the US Bureau of Alcohol, Tobacco, Firearms and Explosives (BATF).