Spin Grind

I Just Bought Two Wilson Wedges (52 & 60) They Said Spin Grind On Them.  I Thought That Spin Grind Was The Same As Spin Milled.  But I Get No Spin What So Ever. Even If I Use A ProV. I Play At A Links Course And I Usually Get Backspin To Stop The Ball On The Second/Third Bounce With My 8-SW (Wilson Fatshafts)

So What Is Spin Grind? 

Spin milling is when machine marks are left on the striking face of the club to increase spin, the rougher face increases the points of contact on the soft cover of the ball.

Spin grinding is an engineering machining method that uses a cup shape abrasive wheel with a moving workpiece to create a fine finish.  Unless of course they are tour grinds, which just refers to the area and angle of the base of a wedge.

Maybe you just aren't hitting them right?

Imagine a cup with a moving piece down the middle - the cup squares up to the surface of the wedge and the moving piece (possibly anti-clock wise) circularises the wedge surface creating a fine finish.......

Tim - that is a pure guess mate but how close

Me and Tim are engineers and sometimes we forget that not everyone else is! 

Basically, the club has been finished with a grinding wheel which makes it smooth faced.  Remember when you were a kid and you used to put your bike upside down and turn the peadals to see how fast you could get the backwheel to spin?  Well imagine covering the back wheel in sand paper then touching it!  An abrasive wheel is a heavy duty version of that and is used for leaving a very fine and smooth finish on metals.  A smooth face means that the only thing gripping ther ball is the grooves and if they aren't sharp there is very little grip so very little spin. 

With a spin milled face, the tool that finishes the face is similar to a drill, but the end is flat rather than pointed.  The flat end cuts away the metal and as it passes over the face it leaves a slight mark in the direction of the cut (like putting stripes in your lawn).  This slightly rough face 'grips' the ball when you hit it and causes more spin. 

Hope that helps

Done a bit of research and I think I know where this confusion is coming from.

Spin grinding is an americanism of what I would call hollow grinding.  This uses a cup or cone shaped grinding wheel where the inside edge of the cup is used as the cutting surface. By using the cup at different angle to the club head this will produce various convex radii.  This method is used only to vary the bounce of the wedge, in effect cutting away the sole of the blade to reduce friction as it cuts through turf or sand, and will have no effect ont eh spin generated apart from affecting the way that the ball is struck.  Vokey have quiet a nice site explaining the various terms here   http://www.vokey.com/tech_central/default.aspx  .  Interestingly they don't really explain the spin milling process but make a vague reference to the maximum CLA value allowed (the surface finish roughness) instead prefering to harp on about groove shape etc:  Think of spin milling as the equivalent of covering the face with sand paper - higher friction, more grip and therefore more spin.

Unfortunately, any modification to your club makes it illegal, so I wouldn't go down that road!  Hit down on the ball and hit it hard with a good follow through.