whats the difference?

i think gunman has a thread somewhere about this...

I would guess that standard mechanical pencils were designed primarily as writing instruments and they tend to have shorter lead sleeves while drafting pencils tend to feature longer sleeves to perform well in conjunction with straight edges and templates that were the required drafting tools prior the advent of software like Auto CAD. Drafting models also tend have enhanced ergonomic grips to prevent slippage and for comfort during long drawing sessions at a drafting table. While you can sketch and doodle with either type, I prefer the balance and feel of drafting models like the Pentel Graph 1000.

I have used both and I prefer drafting pencils. the promecha pencils on JP really rock.

to me at least, it's the same difference between writing with a $1 bic pen and a $70 cross pen. it feels better in your hand since it's heavier. the grip on some drafting pencils is also thicker and, for me, it makes me write more clearly/neatly.

i would maybe get one medium-range drafting pencil to see if you like it or not. essentially, they both do the same thing, but you can totally sense the quality even in a low-end drafting pencil.

the promecha also has a 'label' sort of thing on the end of the pencils. it's a setting that you can turn and it displays the type of lead you are using in there - 6A, 5B, etc. this may come in handy if you have several drafting pencils on your desk at any given time. it also takes the guesswork out of figuring out which lead you had in a pencil in case you refill it.

as for the extentable tips/guides, i have found no use for this although i use my drafting pencil for math notes. in other applications, i am sure it has some purpose.

Consider Drafting Pencils a sub set of Mechanical Pencils. While all Drafting Pencils are Mechanical Pencils not all Mechanical Pencils are Drafting Pencils.

A typical Drafting Pencil will feature a 4 mm long lead sleeve, fixed. Mechanical Pencils have a shorter 2 mm lead sleeve, or a conical sleeve or no lead sleeve at all. Some Mechanical Pencils have sliding sleeves. A true sliding sleeve is the weakest point in the system. It can cause lead breakage. It's main purpose is to act as a retractable sleeve so the pencil can be carried in a shirt pocket. Some Drafting Pencils, like the Ohto Super Promechas and the Mitsubishi uni SHIFT have hide-away lead sleeves. This is not a sliding sleeve. The sleeve is fixed to the inner housing, covering the chuck assembly. The outer housing moves to conceal/reveal the lead sleeve. A true sliding sleeve is housed in the removable end cap of the pencil and is more or less free floating, independent of the chuck assembly.

A Drafting Pencil will generally feature a larger grip that a Mechanical Pencil. Typically the grip is made of either rubber or metal, or a combination of both, though inexpensive Drafting Pencils often have grips made of plastic. The body can be made of either plastic or metal or a combination of both. A typical Mechanical Pencil will be made of plastic and have a plastic or rubber grip. Higher end Mechanical Pencils will often be made of metal, sometimes exotic metals, like Titanium or Stainless Steel. Metal Drafting Pencils age generally made of Brass or Aluminum with some small parts made of Stainless Steel. They are plated with different metal alloys and are typically satin in finish.

A Drafting Pencil will typically have an eraser hidden under the push button, jammed into the lead reservoir. Most inexpensive Mechanical Pencils will have exposed erasers atop the pencil. The eraser for a Drafting Pencil is typically smaller than the one atop the Mechanical Pencil and is usually quite useless. The eraser atop a Mechanical Pencil is larger and generally quite useful. A clean out rod is often found stuck into the bottom of a Drafting Pencil eraser. This is used to clear a lead jam from the long lead sleeve. Mechanical Pencils do not have clean out rods.

Drafting Pencils come in 0.3/0.35 mm, 0.4 mm, 0.5 mm, 0.7 mm and 0.9/1.0 mm. Mechanical Pencils, with 3 exceptions that I am aware of, come in 0.5 mm and 0.7 mm. Some Drafting Pencils come in 2.0 mm lead, like a Lead Holder but it works like a Drafting Pencil. Some Mechanical Pencils of the non-ratcheting variety use lead larger than 0.7 mm

All common Drafting Pencils are of the ratcheting type. That is a button is pressed on top of the pencil to advance lead. A spin-off of this is the shaker pencil. It uses a heavy internal weight and an up and down shaking notion to advance the lead. The traditional push button method can also be employed. Some Mechanical pencils have the push button on the front part of the body close to the end cap. This type is often called a side clicker. I have yet to see a Drafting Pencil designed this way. Some Mechanical Pencils are of the screw type. This is where the pencil is twisted in order to advance the lead.

Most Drafting Pencils will have an industrial look to them with end caps that step down to the lead sleeve. Though not all Drafting Pencils have this industrial feel. The Pentel P200 Sharp series is a good example. While being a true Drafting Pencil the pencils look like simple Mechanical Pencils. Only the 4 mm lead sleeve gives it away! Most Mechanical Pencils are either elegant in design or fanciful in design.

Drafting Pencils are designed for years of service having parts that are easily disassembled for cleaning and maintenance. Most Mechanical Pencils are not designed for easy disassembly, often the plastic parts are glued in place! Most Drafting Pencils will have separate components, like a separate, removable pocket clip. The typical Mechanical Pencil will often have such components attached in an irremovable way or as an integral part of the pencil.

While Drafting Pencils are designed for mechanical drawing, hence the 4mm lead sleeve for gliding around the edges of drafting straight edges and inside templates, they lend themselves to being used as writing instruments. In fact they make excellent writing instruments! If a Mechanical pencil has a long enough lead sleeve it can be used as a Drafting Pencil.

I hope that this helps. 8)