Methods of Marking

Casting

the process of pouring a liquid or suspension into a mold to produce an object of desired shape

Cast

the reproduction of a toolmark or the surface of a tool utilizing a molding material

True or False: casting is suitable for serial number applications

False

Stamping

use of a die to impress a piece of metal

What are some stamping methods?

Roll, pin, hand stamped

What is the most commonly used technique for applying a serial number?

Stamping

What are the downsides of stamping?

Can’t be used on plastic & composite materials

True or False: flat surfaces are required for stamping

True

Impressed

applies tremendous amount of force by pressing

Embossing

art of creating raised patterns on the surfaces of paper, leather, metal or other materials

What is embossing primarily used for?

decorative purposes

What type of effect does embossing result in?

3D effect

Debossing

art of creating indented patterns on the surfaces of paper, leather, metal or other materials

When is debossing mostly used?

packaging or branding

Coining

to stamp & form a metal piece in one operation, usually with a surface design

Vibratory Pencil

handheld, pen-shaped tools, that use a rapidly oscillating carbide-tipped stylus to create permanent, etched markings on hard materials

Does a vibratory pencil engrave or indent?

Engrave

Pin Stamping

a permanent, direct marking process using a carbide pin to indent the marking surface

What are other names for pin stamping?

Dot peen marking or dot matrix

Which stamping method can be used on both plastic & metal?

pin stamping

What is a common firearm manufacturer that uses pin stamping?

Hi- Point

Laser

process of changing a part’s surface with laser light; surface is gradually changed through localized heating of the part

True or False: laser methods require physical contact w/ surface being marked

False

What is a disadvantage of laser methods of marking serial numbers?

when removed, it is near impossible to recover

Electrical Discharge Machining

an electrical process using a spark gap to remove material; accomplished by rapidly recurring discharges between two electrodes separated by a dielectric liquid causing the metal to be removed

True or False: in electrical discharge machining metal is removed from both work piece & tool simultaneously

True

Impact Marking

pneumatic or mechanical stroke systems ideal for high-productivity lines or thick components

When is impact marking used?

heavy-duty parts such as receivers or bolts

Radio Frequency Identification (RFID)

uses an electronic chip embedded in a weapon that carries information about weapon

Electro-chemical Methods

an applicator moistened w/ an electrolyte solution that is connected to an electrical source is placed on stencil bearing the mark

What is the disadvantage of using electro-chemical methods for applying a serial number?

• obliteration is unlikely to be recovered

• can only be used on conductive material

Microstamping

allow for the marking of a weapon’s make, model, & serial number onto a round of ammo each time a weapon is fired

Where are microstamping marks found?

primer & cartridge case