Not all burrs are born equal.  Here is a representative sample of the home market stuff available. 

PETRA - cheap old machine.  My standard for several years for cafetiere and convenient enough to leave in the office kitchen.  Those two square proturbances on each of the top and bottom do the grinding and not the moderately sharp teeth. The outer edges of the burrs are flat where they have rubbed against each other as I have adjusted finer over the years. I have only seen it for sale once since - although the similar "Emide" is appearing occasionally in the UK. 35 ish
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Top.  Screwed to the input hopper.  Bottom - attached to motor and adjusted at the base by a thrust device.  Note the grounds sweeper at the bottom of the picture. Over view.  Round knob is a simple push start.    See here for leak free output hopper.
GAGGIA MM.  Oh dear.  This machine was used for espresso for six months until I upgraded  - it did grind fine enough to choke a Gaggia Classic (after the tweak) but the "U" shaped output hopper is awkward and this grinder is now in storage.  I have seen new burrs for this machine - and they are also not sharp.  The work is done by the six bigger proturbances - the edge nicks seem to be just for channelling.  60 ish
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Top. Note detents for adjustment stops on peripheral ring. Bottom.  Three ground sweepers equi spaced. The fineness is adjusted by turning the input hopper at the top
The Russel Hobbs Grinder.   Also intrinsically the same as the Capresso 551 and the La Pavoni PA
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Looking somewhat akin to the Gaggia MM burrs....  Thanks Kevin Reilly The Capresso 551 and Pavoni PA 
SOLIS 166 (Starbucks barista).  A messy grinder (worse than even the MM).  These are "conical" burrs - the Rocky, MM and Petra are flat. 60 ish
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Top. These do actually cut!  Note the finer channelling teeth at the right of the bottom picture. Bottom.  Note not just the 5 star teeth but the striations on those and the channelling teeth visible at the outside to match those on the Top. This would be a nice grinder were it not for the static and badly fitting output hopper.
MULINO 177 - the updated Solis 166 brought out in 2000.   Designed to be easy to adjust the grind "range" - Thanks Tim Reed.                                                         (Ruler in inches so identical in size to 166.)
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Top Cutting Edge
BODUM ANTIGUA Thanks Peter Oosterhoff.   Note similarity to Solis 166. (Ruler in cm)
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Top Burrs.  Even the plastic holder looks similar to the 166

Bottom Burrs - Not rust - proper coffee!
FAEMA MP78 Commercial grinder From 1978.   Thanks again Peter Oosterhoff.
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Top.  Note similarity including size to Rocky Bottom.   And burr pattern But the other parts are heavier duty
MAZZER SUPER JOLLY.  A serious pro grinder.  Its smaller brother, the Mazzer Mini, is generally considered top of the tree for the serious home chap.  But if you get an opportunity for one of these......  Thanks, Pepe.  450...
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These burrs are 64mm diameter. (The Mazzer Mini's are 58mm and the Rocky's 50mm)  Note that this gives an area 30% larger than the Mini (as Jack pointed out to me)
RANCILIO ROCKY.  A good quality domestic espresso grinder.   It is very similar to the Gaggia MDF.  The burrs are the same in size, sharpness and almost identical on number of teeth but the Rocky scores in that the adjustment indents are set 2.4 times finer than the MDF.  130
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Top.  These teeth are sharp - and ALL cut the bean.   That is a heavy solid brass holder with adjustment screw thread. Bottom.  the peripheral flats are machined - not worn.   Note the chunky brass ground sweepers (directed to a hole through the casing at 3 o'clock)
The ZASSENHAUS is considered to be amongst the best of the manual grinders and is purported to deal with espresso grind happily.  These pictures would bear that out - similar conical design to the 166 etc.  Compare this with the camping version at the bottom of the page - similar shape but the Zass looks as though it has been finished whereas the "No-name" looks like a raw casting.                            Thanks, Johnny.

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A venerable Zassenhaus grinding into a glass beaker
The SALTON Manual Grinder.  A novelty only.  This was mounted on the wall and used as a punishment for noncommunicative dinner guests - it is hard work!  Salton are a British company specialising in solid castings - most of their sales these days seems to be the balance scales with cast brass weights.
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This bit attaches to the wooden handle. Pretty snail pattern burrs. Sorry about the rust. Regretfully not a precision grinder.
"NO NAME".  A cheap, IIRC, (15?) hand, burr grinder.  There is no writing on it anywhere.   I bought it a few years ago in an Aladdin's cave type kitchen shop but I have seen them in camping shops since.   The burrs look quite respectable (not up to the 166 but c.f. e.g. the Gaggia MM) but, of course, the bearings are so imprecise that no consistent grind is possible.  The handle comes off and stores in the input hopper.   The output hopper is a leak free fit and the input hopper has a tight lid and stores enough for a days sailing.
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