Link: http://HarborFreightReviews.com/HFRreviews.html

Item: 24" Aluminum Bar Clamp
Item number: 38183
Retail price: $9.99
Frequent sale price: $5.99
Target price: $4.99 (use a 20%-off coupon)
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This bar clamp is sturdy enough to put some serious pressure on your work, yet reaches 24" and has a quick release. Bought at our target price, this item is only a little more than the plastic ratchet-style clamps that many people are abusing by trying to over tighten. This metal clamp is what's needed for gluing furniture and other projects that require stronger pressure than what the plastic clamps were designed for providing. Use the right tool for the project and "no worries."
We love our 12" ratchet-style clamps and use them for a lot of work around the home and shop. They're suitable for light gluing or for holding aligned boards together while drilling. They've very lightweight and quickly tighten and loosen. For the heavier work, we use a heavier tool -- this aluminum bar clamp is for projects that require more pressure (e.g., most furniture repairs). It weights a bit more and is noticeably slower tightening (uses a screw mechanism instead of a ratchet), but that's the cost of a more heavy-duty tool needed for a 'larger' project.
The aluminum clamp is lightweight and easy to use. For larger projects, it comes in 36-, 48-, and 56-inch sizes. We don't do a lot of woodworking or furniture repair, so it sees little use in our shop. But when it's needed, it's needed. At the low target price it's inexpensive enough to keep on hand even for occasional use.
Bottom line: A good-quality aluminum bar clamp, priced right when on sale at Harbor Freight. Also available in sizes up to 54" for those larger projects.
Link: http://HarborFreightReviews.com/HFRreviews.html

Item: 12" Ratchet Bar Clamp/Spreader
Item number: 46807
Retail price: $6.99
Frequent sale price: $1.99 (with coupon)
Target price: $1.99
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Cheaply made but cheaply sold -- a great deal because the product works and because it's sold at the right price. This is the kind of deal we love. There's not much cost that goes into manufacturing this item; its light-duty plastic and metal components are not fabricated from expensive materials nor is there complex machining involved in the manufacturing process. But it does its job and it does it well, and very importantly, Harbor Freight has priced this item (when on-sale which is very frequently) at a correspondingly low price.
The business model of today is to price most items at what the market will bear irregardless of their intrinsic value (e.g., the cost of materials and workmanship). Harbor Freight frequently bucks this trend by pricing their merchandise not only lower than other retailers but at levels consistent with the intrinsic value of the product. This bar clamp is a cheap little item sold at a cheap little price -- bravo Harbor Freight!
For those who don't understand the purpose of this 12" bar clamp (e.g., those who are going to abuse it by over tightening its ratchet mechanism), this is a light-duty item. For those that use it for its intended purpose such as holding wood and similar pieces together while gluing or drilling, this is a medium-duty item that should stand-up well to normal use. (Hum, that theory of relatively keeps popping up yet again in another context, i.e., use for intended purpose vs. abuse of a tool.) Don't get too annoyed when the orange end caps keep falling off; just snap them back on while remembering this is a cheap little tool and you didn't pay much for it.
Buy at least a pair; when you discover a need for holding two bulky pieces together for gluing you don't want to be caught one short for the job. If you need a lot of holding force, this is not the tool: use Harbor Freight's 24" aluminum bar clamp or if you need a lot of pressure, use a C-clamp instead. You might also consider the small, 6" version which is very handy for those extra small items that need to be held while gluing. Watch out or you'll be paying more for the small 6" clamp than for this 12" clamp. The 6" version has occasionally been on sale for 99 cents, but it's not up as often as the larger size.
Bottom line: Buy a pair and even consider the smaller sized clamps. They're another great deal from Harbor Freight when purchased at our target price of $1.99.