Production Process

MAC Corporation

How the MAC Knife was developed

In 1954, Our Chairman studied in a College of Arts in Chicago, U.S.A. While he was studying abroad, he had a Part-time job in a Restaurant as a Chef. He was given a heavy, dull (blunt), dangerous pointed tipped German knife and was having a hard time using it. Once, he accidently dropped the knife on to the floor. The knife stuck on the floor and nearly stabbed his feet. When he tried to twist the knife and pull it out from the floor, about 3 cm from the tip was broken. The broken blade looked very ugly, so he fixed it by using the whetstone and made the tip round (curved) and put the edge on it. He recalls that after that the knife’s usability had improved very much and his job progressed very well. He thought, why does the kitchen knife’s blade tip needs to be like spear? What’s more, there was no inconvenience with the round shaped tip when cooking.

He returned to Japan in 1958 and had worked in several fields. But his recall of the round shaped tip knife pushed him to establish MAC Corporation
In 1965, to design more safer/sharper/lighter and easy to use knife, MAC Corporation
was established.
Registering more than 2 Patents and the Design, he had released the MAC Knife into the world.
Since then, over 30 Million knives has been sold worldwide.

How the MAC Knife was developed

‘MAC’ Origin

The Trademark ‘MAC’ comes from MACROCOSM which means Big Universe. He had chosen this word from his ambition and wanted our MAC Knives to be used all around the World. From that he took 3 first letters as ‘MAC’.

Production Process

No. Process Description Type Photo
1 Press (2Process) Press out the shape of the knives and the holes to secure the handles.
2 Trichlene Cleaning Washing off the Oil.
3 Quenching (Burn-In)
(3Process)
Go through the Oven under Preheating and then through main Heating under Anoxia by the Temperature of 1030℃ to 1060℃ and then cool down.
4 Cooling Down/
Adjusting (2Process)
Cooling Down by using the Fans to the Room temperature using the vise to adjust the Bents, and then fix the small Distortions by Skilled Craftsman's hands.
5 Sub-Zero Cooling down to -196℃ by using Nitrogen. This makes the Blade's Metal Structure in more high density and aligned which makes the hardness 1to 2 Rockwell up.
6 Reburning Put into an Oven again for Re-burning in about 200℃.
7 Adjusting (2Process) Using a special small Hammer to adjust very small Distortions.
8 Reburning by using
the Lead (2Process)
Reburn the Blade's part which sticks into the Handle to avoid the Blade to break as when welding the Bolster, it gets very hot which makes the Blade material weaker.
9 Blade's Back Grinding Griding the Back part of the Blade to make it straight and smooth.
10 Reburning by using
the Lead (2Process)
Grind the Front side and the Back side of the Blade to make it thin by using the Automatic Grinding Machine.
11 Water Polishing
(2Process)
Water Polishing from the middle part of the Blade to the Edge side, Front and back side, by the skilled Craftsman.
12 Washing and Drying
(2Process)
Wash off the dirt and dry the Blade well.
13 Grinding (4 Process) Grinding the Hollow, the Back Part of the Blade, Border of the Water polished parts, etc.
14 Polishing
(2~4Process)
Polishing the Surface of the both side of the Blade twice by using the Automatic Polishing Machine to get the steps away and smoothen the surface.
15 Welding Bolster
(2Process)
Welding on the right and left Bolsters on to the Blade. Only the Knife with a Bolster
16 High Frequency
Reburning
Reburning the Bolster Part of the Blade by high Frequency Heating Machine. Only the Knife with a Bolster
17 Bolster Cutting
(2Process)
Cutting the Welding part vertically to so that the Handle can be fitted on without getting any space between the Bolster. Only the Knife with a Bolster
18 Bolster Polishing Part 1
(4Process)
Around the Bolster → use #60/#100 for Rough Polishing, Near the Brim → Use #180 Sand Paper to get rid of the step difference, use #60 Vinyl Whetstone and #180 Emery Cloth Whetstone for finishing. Only the Knife with a Bolster
19 Dimple on the Blade
(4Process)
Curving Dimples on the Blade, two times each on the Front side and on the Back side. Only the knife with Dimples
20 Bolster Polishing Part 2
(4Process)
Around the Bolster → Use #100 Sand Paper then use #180 Emery Cloth and #180 Wheel Type and then use #240 Wheel Type for the final Polishing.
21 Satin Polishing
(2Process)
Get the dirt and the rust off from inside the Dimples.
22 Cleaning (3 Process) For putting on the Marks (such as LOGOs) well on the Blade, wash it well by using the detergent, rinse it well, and wipe it well.
23 Putting on the Marks
(LOGO,etc) (13Process)
* Front Side : Electrical Corrosion → Clean → Color (Black/Blue/Red) → Dry
* Back Side : Color (2 colors) → Dry
24 Putting into the
Plastic Bag (2Process)
Avoiding the Blade to get scratched or damaged, we put the Knife, one by one into a Plastic Bag and seal it with a tape.
25 Cutting out the Handle Cut out to the shape of the Handle from the Laminated Plywood Plate and carve into two parts.
26 Polish the Handle for attaching on to the Blade.
27 Handle Attaching
(10Process)
Attaching the Handle on the Blade : Drilling Holes, Polishing.
(Back side, Front side, Middle part)
28 Polishing the Handle
(8Process)
Using the Rough Type and the Medium Type Sand Papers, grind the steps on the Handle and then, using the Cloth Type, polish for finishing up.
29 Putting on Edge1
(Calm Wave Process)
(2Process)
About the width of 10mm of the Edge on the Blade, sharpen it very thin to make the Edge to cuts well.
30 Putting on Edge2
GettingBurr on)
(2 Process)
Sharpen the Edge of the both sides of the Blade to get the Burrs come out on the Edges.
31 Putting on Edge3
Rounding the Burr)
(2Process)
Roundishing the Burrs and get the step curved from the both side of the Edges.
32 Putting on Edge 4
(Finish) (2Process)
Polishing to get the Burrs get roundish from the both sides of the Blade.
33 Care and Inspection
(5 Process)
Checking if any scratches or any defect or any dirt or any printing mistakes on the Knife while wiping it by a soft cloth.
34 Final Inspection
(3 Process)
Checking the sharpeness, any damages, any funny shapes by visually.
35 Packing (7 Process) Packing for delivery. Put the Blade part of the Knife into a sleeve, put it into a Single Box with the Instruction sheet, put the Item Label on the Single Box, put it into the Inner Box, put the Item Label on the Inner Box, put the Inner Boxes into the Carton Box.
36 Delivery ETD MAC Corporation Gifu Factory.

Summary of the Production Process

Kind of Knife Item Number of Processes
With Dimples and a Bolster MCK-105-D/MTH-80/MSK-65 About 104
With a Bolster MBK-110/MBK-95/MBK-85/MKS-105/SO-70/BON-60/
PKF-60/PKF-50/PKF-30/MSB-105
About 96
With Dimples TH-80/TH-50/SSL-130 About 89
Other MAC Knives BK-120/BK-100/BK-80/HB-85/HB-70/HB-55/HB-40/
BS-90/AB-Series/etc
About 83

Sub-Zero Process Explanation

In an another words, we call this Sub-Zero Process as Cryogenic Processing.
Which means, cooling down to under 0℃.
We use this method to make our Knives much better.
Just leaving the knife for several weeks can change the Austenites to Martensite.

After Quenching, there are some Austenites left in the Steel. This Austenites may cause a deviation or crack while leaving it somewhere. In order to change this Austenites to Martensite, Sub-Zero Process is one of the way.
Normally, Dry Ice or Carbon Dioxide or Nitrogen are used.
We use Nitrogen and we cool it down to -196℃. We call this Super Sub-Zero.
After reaching down to the designated temperature, we leave it for 30 minutes, which is said to be the best length of time.
It is said that the Wearing Resistance improves better.
Then, warming back by Air or dipping into a warm water. We call this process as 'Up-Hill Quenching'.
After 'Up-Hill Quenching', we do the Re-Burn Process to stablize it.

We use this Sub-Zero Process for our FKW Series, Superior Series, Ultimate Series, MTH-80/MSK-65/TH-80/TH-50/JU-65/SO-70 and some other items.