hand2mind 50mm Single Pulleys, Pulley for Science Project, Pulley Wheel, Brass Pulley, Science Experiments for Kids, Science Supplies, Teacher Supplies for Classroom Elementary (Set of 5)

The rope tends to jump off the pulley fairly easily and often. Rope less than about 3/16 inch in diameter will jamb between the pulley and the frame when this happens.The pulleys have held up well so far under loads of several pounds.Worked well for an elementary school science fair. Not bad for the price.

These are very nice pulleys, with low friction and moderate wobble. The frames are sturdy. They work with strings or cords up to a little over 4mm diameter, and appear capable of at least 10 lb loads. Cords of 3mm diameter or more cannot "jump" off the pulleys and jam, as sometimes happens with cruder hardware type pulleys. Although these are intended for classroom and demonstration purposes, I found them very useful for practical "block and tackle" light duty applications, particularly since they feature hooks on both ends. They are not as good as ball-bearing pulleys, but for the price are hard to beat. I'll use them again.

Okay for lightweight use-- though you have to remember to feed the string through before it is secured at both ends. I used it to hold a 1200 gram piñata with ⅜ in paranoid and it worked just fine.

These pulleys are a good value for your homeschool student. These are available to our children with our open science supplies. But, these items are only appropriate for small scale experimentation. Wheel grooves aren't deep enough to handle lifting with thin ripe.

The small black pulleys as shown are perfect for in-class pulley demonstrations and exploring simple machines. I ordered 6 bags of these. However, what I received was two bags of the pulleys pictured and 4 bags of cheaper, crappy blue pulleys. I've requested replacement pulleys...I'll adjust my rating when I get what I actually wanted.

Very weak metal used for the hooks. We put weight on four pulleys and the metal bent. Even thought the weight load is reduced exponentially by the pulleys. Hmmmmmm....

My 8th graders used them for Rube Goldberg machines and several fell apart. Cheaply made.

Very, very disappointed with these. Ordered 3 sets at one time; received one set of black pulleys of mediocre quality (as pictured) and 2 sets of blue pulleys of extremely poor quality. Not at all as pictured. Due to time constraints, I tried to utilize in the classroom anyway - poor construction meant high levels of frustration in class. We couldn't even use the blue sets due to the poor quality.

No esperaba mucho pero Relación precio calidad están excelentes. Se sienten resistentes y giran muy bien