Monthly Archive January 5, 2021

The operation process of the machining cost center of mechanical parts is as follows:

1. Inquiry process:

Receive business, purchase new products, material notice, information – > inquiry to understand the content, CNC machine tool processing to confirm the demand, seek suppliers to check the quotation before similar products, manufacturer’s quotation, unit price confirmation, submit to the supervisor for approval, respond to relevant units to track and confirm the unit price and other information, feedback and report.

2. Valuation process:

Following the content analysis of the evaluation form of business development (whether it is necessary to ask for inquiry outside the contract), fill in the original of the evaluation form approved by the supervisor and send it to the business department to track the confirmation of the quotation. The business will submit the confirmed original quotation details to the cost center and input them into the computer for final confirmation of each process cost (including processing, outsourcing, purchasing materials, etc.)

3. The proportion of cost analysis;

The proportion of materials in the whole product sheet is 30% – 50% for the panel and 50% – 80% for the heat sink

After work, the cost center should go to the production line to understand the actual manufacturing process, regularly capture the change trend of the aluminum ingot Market and the exchange rate of each currency on the Internet, care about the aluminum industry market, and quote the most reasonable unit price.

Quotation method and standard

1. Calculation method of material weight:

Weight formula:

Product gross weight = sectional area X specific gravity x [product length + saw blade (4-5mm)]

The specific gravity of aluminum extrusion is calculated as 2.8x103kg/m, while that of aluminum plate is calculated as 2.75x103kg/m.

② If the length of the above product is 220mm, the weight of the product is:

(220+5)x3.159=710.8 g

2. Calculation formula of sectional area:

① . equilateral triangle:

Area s = a * H / 2 = 0.433a2 or 0.578h2

② Right triangle:

Area s = a * B / 2 h = a * B / C

③ . flat quadrilateral and rectangle:

Area s = b * h

④ . diamond shape:

Area s = D * H / 2 a = 1 / 2 D

⑤ . Square:

Area s = a * a d = 1.414 a

⑥ . trapezoid:

Area s = (a + b) * H / 2 or m * h, M = (a + b) / 2

⑦ . round:

Area s = π / 4 * D2 or S = π / 4 * D2

⑧ . ellipse:

Area s = major axis radius * minor axis radius * π = a * b * π

⑨ . ring:

Area s = π / 4 (d2-d2) or S = π / 4 (r2-r2)

⑩ . fan shaped:

Area s = π R2 * а / 360 or S = R / 2 * l

(11) bow shape:

Area s = L * r / 2-C (R-H) / 2

(12) parabolic arch

Area s = 2 / 3B * h

3. When calculating the cross-sectional area of the product, the subsequent processing loss of the product, such as grinding allowance, should be considered.
4. Calculation method of the number of plates to be cut:

The specifications of the plate materials used are as follows: 1.22m * 2.44m, 1m * 2m, 1m * 2.2M, etc.

The calculation method is as follows:

For example: for t2.0 aluminum plate, when the blanking size is 100 mm * 50 mm and 1.22 m * 2.44 m plate is used, the blanking size is:

(2440 / 100) * (1220 / 50) = 576pcs

That is to say, one aluminum plate of this specification can produce 576pcs products.

Since the weight of a 2.0 * 1.22 * 2.44m aluminum plate is 16.5kg, the weight of each product is calculated as follows:

16.5 * 1000 / 576 = 28.65g, that is, the weight of each product is 28.7g

5. The proportion of common materials is as follows:

Aluminum: 2.78g/mm2 iron: 7.8g/mm2 copper: 8.94g/mm2

6. The quotation basis for each process is as follows (HK $):

1) As for the unit price per kilogram of materials, it depends on the international market and the types of products

Generally speaking, the unit price of H / s material is 28-30 HKD / kg, while that of F / P material is 30-32 HKD / kg

Copper material is quoted at 65-70 HKD / kg

Copper coil is quoted at 70-75 HKD / kg, aluminum coil is quoted at 32-35 HKD / kg

The price of SPCC is 7-9 HKD / kg, while that of SECC is 8-12 HKD / kg

2) . cutting:

According to the extrusion area, product shape and cutting length, the width and thickness of the extrusion are as follows:

Panel: 150 MM-200 mm 0.6-1 / PCS

100mm—150mm 0.3–0.7/pcs

50mm—100mm 0.15–0.4/pcs

Below 50 mm 0.1 — 0.2/pcs

Large heat sink (AMP)

0.8-1.0/pcs above 200 mm

150mm—200mm 0.6—1.0/pcs

100mm—150mm 0.3—0.7/pcs

50mm—100mm 0.15—0.4/pcs

Small radiator (sPS / UPS)

0-1.0/pcs above 200 mm

150mm—200mm 0.6—0.8/pcs

50mm—100mm 0.15—0.4/pcs

0.1-0.2/pcs below 50 mm

CPU radiator: 0.03-0.15/pcs

3) . plastic surgery:

According to the actual situation, thickness and customer requirements, it is generally as follows:

Appearance panel class:

0-1.0/pcs above 200 mm

150mm—200mm 0.3—0.5/pcs

0.15-0.3/pcs below 150 mm

Large radiators:

0-1.0/pcs above 200 mm

150mm—200mm 0.5—0.8/pcs

80mm—150mm 0.3—0.5/pcs

0.1-0.4/pcs below 80mm

4) . stamping:

Calculated by the number of stamping times, the unit price varies according to the tonnage of the punch used and the rise and fall of the product. As follows:

Radiator:

Below 8t-15t: 0.03-0.1/time 15t-25t: 0.05-0.12/time

35t: 0.08-0.18/time 45t-50t: 0.1-0.2/time

60t: 0.15-0.3/time 110t: 0.3-0.5/time

160t: 0.5-1.0 per time

Panel class:

15t: 0.35-0.45/time 25t: 0.4-0.5/time

35t-50t: 0.5-0.6/time 60t: 0.6-0.7/time

110t: 0.7-1.0/time 160t: 0.9-1.2/time

5) Drilling / tapping: in principle, it depends on the number of holes, but it is different for multi axis tapping.

In general, H / S is 2-3mm in diameter, 0.05-0.075 per time in depth below 8mm, and 0.1-0.15 per time in case of more than 5 holes

Depth 8mm to 15mm: 0.1-0.15, many holes (more than 5 holes)

15-0.2 per time

The diameter is more than 4 mm; the depth is less than 8 mm: 0.075-0.1; the number of holes is more than 5

15 – 0. 25 per time

More than 8 mm depth: 0.12-0.2, more holes (more than 5 holes),

15-0.25 per time

It can be used for large H / s, 2-3 mm in diameter, 0.075-0.1 per time in depth below 8 mm, and 0.1-0.15 per time in case of more than 5 holes

The depth is 8mm-15mm: 0.12-0.2, with more holes (more than 5 holes)

15-0.25 per time

If the diameter is more than 4 mm, the depth is less than 8 mm, 0.12-0.15, and there are more holes (more than 5 holes), then 0.25-0.35 can be used once

More than 8 mm in depth: 0.15-0.3, more holes (more than 5 holes)

3-0.4 per time

The multi hole drill can be used for one time, and the tapping unit price depends on the situation, which is almost the same as drilling.

6）。 Chamfering: the unit price depends on the chamfering size, depth, product weight and the number of holes.

The panel diameter is less than 6 mm: 0.05-0.08/hole

Large radiator: about c0.5: 0.025–0.05/hole

Above c1.0: 0.075 — 0.1/hole

Small radiator: about c0.5: 0.013-0.03/hole

Above c1.0: 0.035-0.05

7) . milling hole: depending on the size and depth of the hole

General milling teeth: (over 15mm): φ 6: 0.15-0.25/hole.

8) . milling plane:

Each flat inch is calculated as: 0.25-0.4, depending on the size of the area.

9) . CNC processing:

Generally, it is calculated at 1.7 yuan / min, and it is related to the number of tool setting times. Rough and finish milling depends on the appearance requirements of the product

The unit price is different.

A: Rough milling is estimated according to the cutting speed of 250mm-300mm per minute, and if finishing milling is needed, it is x2 times.

B: Both ends of the mill, regardless of size, are calculated according to 2.0 yuan.

C: The front side needs to be refined with a fine knife, and the non front side needs to be processed with a sharp knife.

10) . deburring:

It is related to the shape of cross section, ranging from 0.05 to 1.0 per time

11) . grinding:

According to different customers of different product shape, different surface requirements

Generally 0.08-0.2 HKD per square inch, depending on the thickness of the line

12) . sandblasting:

According to the requirements of different customers, sand size and brightness

Generally, it is calculated as 0.08-0.15 HKD per square inch, otherwise. 80 × 1.1 if there are blade teeth,

More than 100 × 1.2

13) . baking paint:

0.06-0.08 HKD per square inch for white and black paint and 0.06-0.08 HKD per square inch for yellow paint

0.07-0.1 HKD, 0.15 HKD per square inch for special colors.

For the following products, the cost of baking paint is as follows:

1.115/652tb1502 baking yellow paint

colour

number

Amount of paint

Unit price / kg

Cost / PCS

Amount of solvent

Unit price / kg

Cost / PCS

yellow

Z01-H159A

0.15KG/PCS

27HKD/KG

4.05HKD

0.3KG/PCS

9HKD/KG

2.7HKD

In1542 for each paint

(4.05+2.7)/154=0.044 HKD

If the loss is 10%, the cost is: 0.044 * 1.1 = 0.048 HKD

Therefore, the cost center of baking yellow paint is 0.048 * 1.2 = 0.06 HKD / in2

2.040/1403-6380-0 baking black

colour

number

Amount of paint

Unit price / kg

Cost / PCS

Amount of solvent

Unit price / kg

Cost / PCS

black

CE7017F12

0.1KG/PCS

27HKD/KG

2.7HKD

0.15KG/PCS

9HKD/KG

1.35HKD

And the baking area is 101in2, that is, the paint used for each in2 is 101in2

(2.7+1.35)/101=0.04 HKD

If the loss is 10%, the cost is: 0.04 * 1.1 = 0.044 HKD

Therefore, the cost center of baking yellow paint is 0.04 * 1.2 = 0.055 HKD / in2

14) . degreasing:

For smaller H / s with larger area, it should be calculated according to the area. For the blind hole degreasing, according to the customer’s high quality requirements and calculation.

15) . oxidation:

The unit price is related to the oxidized color, weight and oxidized area.

Panel type: generally, whether to calculate by area depends on different extrusion shape.

Radiator: it is generally calculated by weight, but it is also calculated by area for H / s with larger area.