How are metal files made?

im pretty sure the question was how are metal files made not office or computer files. and i have the same inquiry. i don't know what it is i suppose you would anneal the material first then carefully using a hot chisel set of very fine edges to incrementally cut one blade at a time up the work piece. dress it clean it then harden to like 6 or 8 Rockwell i think. maybe some kind of mill or lathe tooling. but aside from that i haven't been able to find much info on the topic.

Metal files are made using file making machinery:

1) "File Master Machine:
We have carved a niche for us in manufacturing and exporting the file master machine. Our assorted machinery are used for diverse range of functions. These kinds of machinery are used for production of following types of files:

For making Creasing Of Office files with step Gauge.
For Making Creasing Off Lever Arch Files
For Hole of Clip Fitting of Lever File.
For Ring Hole Cutting of Lever File
For Ring And Corner Embossing Of Lever File.
For making Holes of Office Files.
Front and back gauge for Easy and accurate Operation.
Foot Operated Mechanical Clutch Model.
1 Hp Electric Motor.
Totally covered Model.
Multipurposed Machine."

"Rotary File Creasing Machine:
We are one of the leading manufacturer and exporter of Rotary Creasing Machine. Being committed towards client’s satisfaction, we also provide customized solution to our clients. The features are summed as under:

For making Creasing Lines of Office File.
Six to Eight Creases in One Single Pass of Material.
Production 70 to 80 Files Per Minute.
Creasing Distance and Depth Can be adjusted.
Creasing Width can also be adjusted.
0.5 Hp Electric Motor.
Metal Platform With Gauge."
Source and further information:
http://www.indiamart.com/ajyamistry-sons/file-manufacturing-machinery.html

Further information:
"Saw and File Manufacturing in Brooklyn in 1884":
http://www.hyperkitten.com/tools/hwpeace/sawmaking_in_brooklyn.php


2) "Samuel Osborn and Company was a steelmaker and engineering tool manufacturer situated in Sheffield, South Yorkshire."

"In 1851 he set up on his own as a file manufacturer with premises in Broad Lane which were named Clyde Works. Within 5 years his company expanded and he rented a six - hole crucible furnace on Calver Street in the city centre, whilst only the following year he set up a tilt and forge in the Philadelphia district of the city, the new site being named Brookhill Works.
Osborn, like many other steel makers, showed an interest in his workers health and in particular two of the major illnesses which affected the file making industry: grinders asthma and lead poisoning. By 1864 he discovered an amalgam to replace the soft bed of lead in which the files were placed when being cut by hand. To reduce contact between his workers and lead he developed a file cutting machine although the craftsmen were opposed fearing job losses and a loss of quality in their product, neither being proved to be true."
Source and further information:
http://en.wikipedia.org/wiki/Samuel_Osborn_&_Company