Wood working04.01.2017

Quality handles from birch planks

Marttiini’s Nordic roots and traditions are prominently featured in the company’s knives.

Marttiini’s Nordic roots and traditions are prominently featured in the company’s knives.

Relying on professional skill and modern technology in machining wooden handles, Marttiini produces belt knives and other types of knives from its base in Rovaniemi for customers around the world.

The Marttiini company dates as far back as 1928 and its operations are strongly rooted in traditional Finnish knives, where wood, leather and reindeer antler bone meet modern materials. In addition to traditional birch, Marttiini also uses curly birch, rubber, plastic and, to some extent, plywood to manufacture handles for its knives. The birch handle remains a popular choice, however.

Customers value light Finnish birch in the handles of Marttiini’s knives.

Customers value light Finnish birch in the handles of Marttiini’s knives.

Marttiini Production Manager Jari Halme knows what customers want in a wooden handle: 

“We manufacture wooden handles from Koskisen’s 32-mm unedged, air-dried birch planks. Generally, we use grade A material. Our customers especially value light Finnish birch that is as monochromatic as possible and has no knots or marks made by insects, and the high-quality birch raw material supplied by Koskisen is ideal for this purpose.”

Over the years, Marttiini has also used grade B material, but grade BSW and grade A materials have established their place precisely for their light colour. Grade BSW differs in quality from grade A in its slightly darker heartwood. It also requires a bit more machining than grade A material.

“We have sought our grades together with Koskisen Sales Manager Raimo Kämppi with the goal of minimising the amount of reject material in the planks,” explains Marttiini’s Purchasing Manager Pirjo Linho.

Air-drying is also an important criterion in selecting the product.

“Air-dried birch retains its natural lightness very well. If the planks are dried mechanically, the colour tone darkens and our customers do not want that,” says Halme.

Machining birch planks into handle blanks

Before a birch sawn timber is machined, the air-dried birch is dried further at the Marttiini factory to joinery standards, i.e. to roughly 5–8 per cent moisture. After that, it’s time to begin carving out the shape of the handle, and the birch plank is sawn into strips 30–40 mm wide. The standard thickness of the birch plank has been set at 32 mm to ensure that the entire plank can be used as efficiently as possible. The sawn strips are then cut into pieces roughly 120–130 mm long for the handles; these are called handle blanks.

Parallelogram handle blanks are turned on a turret lathe, with one handle taking no more than 7 seconds to finish.

“Marttiini uses two lathes. The new CNC lathe is a unique piece of machinery that no other knife manufacturer has. It produces a slightly better finish than the older lathe that uses compressed air,” explains Halme.

The lathe is used to carve the handle blank into its final shape and to make all the holes necessary for assembling the knife. All that’s left is the finishing touches: a light sanding and a coat of wax or varnish.

“The machining method for the handles has not changed much over the years, but modern technology has enabled faster production and greater dimensional accuracy in the final product. We still have a lathe for machining the handles manually, but the production volumes are considerably smaller and it takes more time to finish the handle,” says Halme.

Knife takes final shape in assembly

In the assembly stage, the finished handle and the blade are attached using rivets. Rivets are metal pieces in between the blade and the handle or at the end of the handle. This is the stage that reveals whether the wood material was dried correctly. A handle made of wood that is too moist may change its size, in which case the fixings could become loose.

“All of the holes required for the blade are made on the lathe. In practice, the blade slides into a groove in the handle and the wood grips the blade. The shaft of the blade is thus inside the handle,” says Halme.

The blade is kept in place in the handle either with glue or rivets. Riveting is the more traditional method used for blades that are inside the handle, but with the improvement in glues, it has become increasingly common to glue the blade into the handle.

“The majority of customers, for example, in the United States, prefer blades that are inside the handle, so we use the traditional riveting method to secure the blade,” explains Halme.

After the blade is fixed in the handle, it is sharpened and engraved, and the knife’s journey around the world to the final customer through thousands of distributors can begin.

Over the years, as many as 30 million wooden Marttiini handles have been delivered around the world. Professional skill, experience and the right materials are, and always will be, the secret to Marttiini’s high-quality knives.

For more information about Marttiini and the company’s products, please visit their website.

You can get to Marttiini’s online store here.

Handles made from Koskisen’s air-dried birch sawn timber is a popular choice in Marttiini’s knives.

Handles made from Koskisen’s air-dried birch sawn timber is a popular choice in Marttiini’s knives.