Engineering and Design

At Holt Bladeworks, we incorporate a wide variety of engineering disciplines in conjunction with the best materials to produce a world class knife at a fair price.  Every detail of our knives has been carefully crafted to meet this goal.  We do not mean to brag, but as the potential next owner of this gentleman's flipper we think you should know:

  • We utilize the highest quality of blade materials, whether that be DamasteelBohler M390, or Crucible CPM20CV.
  • We designed our pivot interface to tolerate the large lateral and radial forces that destroy weaker, hidden stop pin designs.
  • All of our fasteners come from the industry leader in folder hardware manufacturing.
  • Our shop dog claims these knives are the best knives ... ever.

The hidden stop pin is a common pivot design, that is mainly popular due to its ease of manufacturing.  This design typically includes a stop pin that is pressed into the handle, with a frown shaped travel path cut out of the blade.  This design makes the blade incredibly weak - especially to lateral loads - and predisposed to fracturing.

The lack of cross sectional thickness is an obvious reason for this weakness, but this issue is further compounded during the heat treat process.   To obtain the right hardness, the blade must be taken from around 2000 degrees to room temperature within a very short period of time.  The frown feature creates an unfavorable ratio of volume to surface area, which means it will reach room temperature much faster than the rest of the blade.  This rapid cooling results in a brittle pivot cross section that is prone to fracturing and possibly failing even under moderate use.

Common Hidden Stop Pin
Specter Pivot Design

Holt Bladeworks knives are  designed to be much more than just letter openers.  Our pivot is built around a quarter inch, hardened, 416 stainless axle, and its design is reversed from the more common approach.  It uses a radial or floating stop pin that is pressed into the blade, with a travel path milled on the inside of the handle.  This design choice maximizes the blades cross sectional thickness, which greatly increases lateral strength.  The smaller amount of surface area and greater volume means it is less susceptible to brittleness from the heat treatment process.  For those of you who require a knife that is more than just a letter opener, these knives are designed to be up to the task. 

The detent is the heart and soul of a flipper.  It is responsible for the speed and ease of blade deployment.  Months of design work went into perfecting the detent mechanism for the Specter.  The initial design used a ceramic ball, which is a popular choice among many knife makers.  When tuned properly, this design works well, but the results are not especially consistent.  Changing the depth of the ball - by even a thousandth - can have a dramatic effect on the flipping action.  This inconsistency between knives made it a clearly undesirable design choice.

The first production design was an integral detent system and can be found on the first 120 released Specters.  In this design the detent, ramp, and tuning pad were 3D machined directly into our hardened 440C (bearing steel) locking insert.  A big benefit of this design was the tuning pad, which allowed for precise depth placement of the detent into the blade's detent hole.  This design was ultimately retired in favor of a new design that is unique to Holt Bladeworks.

V1 Integral Detent
V2 User Adjustable Detent

The V2 design is an Adjustable Detent System (patent pending).  It contains a CPM154 hardened cylinder that is cut into the lock face.  It is a much simpler design than our previous, but it provides all of the same functionality ... and then some.  The detent is set low in the lock insert, which completely removes the need for a ramp on the insert or the blade.  The part that we are most excited about with this new design is the detent adjustment screw.  It is a simple solution that allows for user adjustability.  The desired stiffness of the flip varies from person to person, and we believe the knife should be able to vary as well.  

There are many ways to design a lock on a folder, and the most common approach on lower quality knives is to use the face of the titanium lock bar.  There are two main problems with this design.  The first is that a titanium and steel interface will suffer from galling.  Overtime, the titanium will tend to smear and snag on the lock face of the blade, producing a catchy feel.  A slight variation to this design is to apply a thin layer of carbide - carbidizing - to the titanium lock bar. While this does solve the galling issue, it does not address the other issue with this design.

The second issue with this design is that the correct angle cannot easily be cut on the face of a titanium lock bar.  With this design, the titanium lock face is a 90 degree angle, and the blade lock face is machined with a slight curvature to accommodate the poor fit.  

Titanium Lock Bar as Lock Mechanism
Specter CPM154 Lock Mechanism

The sharp 90 degree angle creates a very small point that will absorb all of the force required for locking, and that force will cause it to wear prematurely.  This wear and compression of the titanium results in a lockup that becomes progressively late, and is what drives the need for early lockup on folding knives. 

Instead of designing the our knives to accommodate these issues, we have chosen to simply design the issues out of our knives.  We insert a hardened CPM154 lock and cylindrical detent into the handle lock bar.  This solves the galling issue and it does not wear in any significant way.  Additionally, it allows the proper lock geometry to be machined on the lock face.

All Holt Bladeworks blades are made using only the highest quality and best suited blade material.  Selecting the right blade material is all about finding a balance between edge retention, corrosion resistance, and hardness.  We have two primary blade materials: Bohler M390 and Crucible CPM20CV.  The are both classified as  Super Steel, and based on the balance of edge retention, corrosion resistance, and hardness they are undeniably some of the best steels currently in production.  

Damasteel blade material is an option available in our Prestige grade knives.  Like the M390, Damasteel is a stainless powdered metal.  A Damasteel blade has good edge retention, and corrosion resistance, but where it really stands out is its' raw beauty!  This steel has some of the most interesting patterns of any stainless Damascus.

Our blades ride on caged ball bearings that are either 440C stainless steel or ceramic.  Hardened and polished washers are inserted between the titanium handles and the bearings.  This is important for a couple of reasons, the first being that the bearings are considerably harder than titanium.  With continued use, the bearings would quickly destroy the uniform surface on the titanium and degrade the smooth flipping action of the knife.  The second reason is that the washers provide a smooth, consistent surface for the bearings to roll against.  This same surface cannot be reproduced by a mill with titanium handles.


Your knife arrives at the door and every aspect is perfectly customized according to your request.  A few weeks later - after using the blade to dig in the back yard (blasphemy, we know) - you start to notice scratches in the mirror finish blade and handle anodization.  You grab some sand paper and start trying to work out the scratches, but it only makes things worse.  At this point, disappointment is setting in and it looks like the knife will need to be professionally refinished. While we are more than happy to schedule a Spa Treatment for your Specter, we want to help avoid that disappointment from the beginning.  To this end, there are a few key pieces of information to keep in mind when customizing your knife:

  • Titanium is a metal, and like all other metals it will scratch and show wear over time.  Stone Washed finishes tend to hide these scratches better than other finishes.
  • Anodization is a chemical process in which an oxidation layer forms on the titanium.  Like all other forms of oxidation, the titanium anodization can be scratched and worn off over time.  Think of the anodization as a layer of paint, rather than an indestructible truck bed liner, and you will not be disappointed. 

Near Mirror

Near Mirror - Texture
Near Mirror - Reflection


Satin - Texture
Satin - Reflection

Stone Washed

Stone Washed - Texture
Stone Washed - Reflection

Black Washed

Black Washed - Texture
Black Washed - Reflection
Satin, In the Nude
Satin, Anodized
Dual Anodized
Stone Washed, In the Nude
Stone Washed, Anodized
Anodized, Stone Washed
Plain Pivot Pin
Relief Pivot Pin
3 Spoke Pivot Pin
6 Spoke Relief Pivot Pin
Bullseye Pivot Pin
3 Spoke Relief Pivot Pin

Achieving an exact and repeatable anodization color can be challenging, as there are many factors involved in the process.  It is also important to note that the voltages associated with our colors may not be exactly the same with other makers, but the voltages are most likely similar.  With all of this in mind, here is the process we believe gets you the best end result:

  • When an order is placed simply choose the desired anodization finish (ie: In the Nude, Dual Anodization, Fully Anodized, etc.).
  • Before an order is started, we will confirm the final details being requested.  During these conversations we will work together to determine the voltage that meets your desired outcome.  For example, the end result of this conversation might be a note on your order similar to this: "Looking at 74V, with a preference towards more purple."
  • While completing an order, we will review the order notes and adjust the voltage within +/- 1 volt to achieve the desired result.  This ability to slightly adjust the voltage allows us to handle variations in the posted images, anodization setup, and your requests.

We have a number sample anodization pictures for the voltages and different anodization finishes available.  Loading them on the website can be a bit slow, so we currently store them on our Google drive.