Welcome to Auto Parts Forum
Whether you are a veteran automotive parts guru or just someone looking for some quick auto parts advice, register today and start a new topic in our forum. Registration is free and you can even sign up with social network platforms such as Facebook, Twitter, Google, and LinkedIn.
By Erica Zhu Feilong Jiangli
The materials used in making molds are called molding materials. The sand molds are mainly molded sand and core sand, which are composed of sand, binder and additives.
1.Molding materials should have the following properties:
（1）Plasticity: molding sand and core sand are easy to form under the action of external forces.
（2）Sufficient strength: molding sand and core sand are not easy to destroy under external force.
（3）Fire resistance: molding sand and core sand are difficult to soften, sinter and adhere at high temperature.
（4）Permeability: molding sand and core sand must be easy to ventilate after compacting.
（5）Concession: molding sand and core sand can be compressed when cooled.
2.Pattern and core box
The pattern and core box are tools for making moulds and cores.
The shape of a casting to form a shape equivalent to the external shape of the casting. The core forms the inner cavity shape of the casting, and the core box is the tool for making the core.
Sand moulds and core boxes are used for multi-purpose wood casting. Metal mold, plastic mold and other patterns for special casting.
According to the different methods of modeling operation, it can be divided into:
（1）Manual molding: sand filling, compacting, mold lifting and so on mainly have the manual completion, the operation is flexible, the productivity is low, mainly uses in the single piece small batch production. There are many specific methods of manual modeling: whole mold modeling, three-box modeling, scraper modeling, false box modeling and so on.
（2）Machine Modeling: Mechanization of sand filling, compacting and moulding, high productivity and large investment, mainly used for mass production
4.Technical problems to be solved in sand casting
（1）The choice of pouring position: the main processing surface and large plane of the casting should be facing down, and the part of the Dian wall of the casting should be placed at the bottom.
（2）Selection of parting surface: plane parting surface should be adopted as far as possible, the number of parting surface should be as small as possible, so that all or most of the castings are placed in the same sand mold.
（3）Drawing inclination and casting fillet: In order to start the mold conveniently, the mold should have a certain drawing inclination, the higher the mold, the smaller the slope value: the inner wall inclination is larger than the outer wall inclination. In order to prevent the casting from producing stress and cracks at the wall joints and corners, the casting wall joints and corners should be designed into rounded corners.
We provide high-quality auto parts for Peugeot, Citroen, Volkswagen, Skoda, Audi and SEAT, from engine parts to electrical parts, from brakes to clutches.
The following products will be on sale from January 14, 2021 to February 13, 2021, which will save you a lot of money.
if you need help，you can contact us：[email protected]
view us web to know more：https://www.tonnano.com/en-US/index.html
By Hot Ajax
I have 09 Tacoma. Their OEM pads are great for stopping power, but they leave a dark residue on the wheel cover. Any of you gentlemen have any suggs?
I typically get 4o,000 plus out of a set of OEM pads. Like I said, they stop good, and they're easy on the rotors.
Thanks in advance.
By Joe Pagone
I have been a mechanic for many years. I used to buy Napa Auto Parts almost always. I felt the parts were good quality, although more expensive than others. It does not pay to install poor quality parts on a car, they come back, and bite you! Unfortunately, a few years ago it seems Napa changed their policy on quality. This happened around the time they totally changed the on-line site. Around the same time, I started looking at Rock Auto on-line. Rock Auto offers each part by a few different manufacturers, quality levels, and prices. I started noticing that despite Napa still charging higher prices, they were now supplying the cheapest, lowest quality parts instead of the better quality they were known for. Given that, why would a person order from Napa, when Rock Auto is surprisingly lower priced, and you have a quality level choice . Napa seems to be riding on their previous well known name, while keeping the prices artificially high.
Some prime examples of this is, I purchased a starter solenoid, (eckland, Napa's electrical brand), as a preventative measure. The third start-up, after installing, the solenoid froze in the on position, with key off, and kept the starter spinning and engaged until I could unhook one battery terminal. Burned up the relay, starter, and a couple wires. I purchased a rebuilt alternator, took it from the box, and turned it, it felt rough turning, as if there was dirt in the bearing race or defective bearing components. I purchased Napa's best fuel pump, and it was very noisy from day one. I purchased a set of Napa Branded, 2 ton each, jack stands. One of them had a defective casting that would not allow the stop to lock in place. Although it seemed it locked, when weight was applied, it fell. I purchased rebuilt Ford Front calipers from Napa, and with in one year, the unplated soft steel bleeder screws has rusted solid to the caliper!
Are other people seeing this too??
Complete Conversion for a HSV VF LSA
Date Listed:27/03/2020 Last Edited:27/03/2020 Make:Holden Special Vehicles Warranty:yes Condition:used Visit us @ Car Part.